/LeetCode

LeetCode Algorithms with C# and Java

Primary LanguageC#

LeetCode

LeetCode Algorithms with C#, Java and Python

No. Question Difficulty Solution Status
1 Two Sum Easy C#, Java, Python, JS ✔️
2 Add Two Numbers Medium C#, Java, Python ✔️
3 Longest Substring Without Repeating Characters Medium C#, Java ✔️
4 Median of Two Sorted Arrays Hard C# ✔️
5 Longest Palindromic Substring Medium C#, Java ✔️
6 ZigZag Conversion Medium C#, Java, JS ✔️
7 Reverse Integer Easy C#, Java ✔️
8 String to Integer (atoi) Medium C# ✔️
9 Palindrome Number Easy C#, Java ✔️
10 Regular Expression Matching Hard ➖
11 Container With Most Water Medium C#, Java ✔️
12 Integer to Roman Medium C#, Java ✔️
13 Roman to Integer Easy C#, Java, JS ✔️
14 Longest Common Prefix Easy C#, Java ✔️
15 3Sum Medium C#, Java, Python, JS ✔️
16 3Sum Closest Medium C#, Java, Python ✔️
17 Letter Combinations of a Phone Number Medium C#, Java ✔️
18 4Sum Medium C#, Java, Python ✔️
19 Remove Nth Node From End of List Medium C#, Java ✔️
20 Valid Parentheses Easy C#, Java, Python, JS ✔️
21 Merge Two Sorted Lists Easy C#, Java, Python ✔️
22 Generate Parentheses Medium C#, Java ✔️
23 Merge k Sorted Lists Hard C# ✔️
24 Swap Nodes in Pairs Medium C#, Java, Python ✔️
25 Reverse Nodes in k-Group Hard C# ✔️
26 Remove Duplicates from Sorted Array Easy C# ✔️
27 Remove Element Easy C#, Java, Python ✔️
28 Implement strStr() Easy C#, Java ✔️
29 Divide Two Integers Medium C#, Java ✔️
30 Substring with Concatenation of All Words Hard ➖
31 Next Permutation Medium C# ✔️
32 Longest Valid Parentheses Hard C# ✔️
33 Search in Rotated Sorted Array Medium C#, Java ✔️
34 Find First and Last Position of Element in Sorted Array Medium C#, Java ✔️
35 Search Insert Position Easy C# ✔️
36 Valid Sudoku Medium C#, Java, Python ✔️
37 Sudoku Solver Hard C#, Java ✔️
38 Count and Say Medium C# ✔️
39 Combination Sum Medium C# ✔️
40 Combination Sum II Medium C# ✔️
41 First Missing Positive Hard C# ✔️
42 Trapping Rain Water Hard C#, Java, Python ✔️
43 Multiply Strings Medium C# ✔️
44 Wildcard Matching Hard ➖
45 Jump Game II Medium C#, Java ✔️
46 Permutations Medium C# ✔️
47 Permutations II Medium C# ✔️
48 Rotate Image Medium C#, JS ✔️
49 Group Anagrams Medium C#, Java, Python ✔️
50 Pow(x, n) Medium C# ✔️
51 N-Queens Hard C# ✔️
52 N-Queens II Hard C#, Java ✔️
53 Maximum Subarray Easy C#, Java, Python ✔️
54 Spiral Matrix Medium C#, Java ✔️
55 Jump Game Medium C#, Java ✔️
56 Merge Intervals Medium C#, Java ✔️
57 Insert Interval Medium C#, Java ✔️
58 Length of Last Word Easy C#, JS ✔️
59 Spiral Matrix II Medium C#, Java ✔️
60 Permutation Sequence Hard C# ✔️
61 Rotate List Medium C#, Java, Python ✔️
62 Unique Paths Medium C# ✔️
63 Unique Paths II Medium C#, Java ✔️
64 Minimum Path Sum Medium C# ✔️
65 Valid Number Hard C# ✔️
66 Plus One Easy C#, Java ✔️
67 Add Binary Easy C#, JS ✔️
68 Text Justification Hard C# ✔️
69 Sqrt(x) Easy C# ✔️
70 Climbing Stairs Easy C#, Java ✔️
71 Simplify Path Medium C#, Java ✔️
72 Edit Distance Hard C# ✔️
73 Set Matrix Zeroes Medium C#, Java ✔️
74 Search a 2D Matrix Medium C#, Java, Python ✔️
75 Sort Colors Medium C#, Java ✔️
76 Minimum Window Substring Hard C# ✔️
77 Combinations Medium C# ✔️
78 Subsets Medium C#, Java, Python ✔️
79 Word Search Medium C#, Java, Python, JS ✔️
80 Remove Duplicates from Sorted Array II Medium C#, Java ✔️
81 Search in Rotated Sorted Array II Medium C#, Java ✔️
82 Remove Duplicates from Sorted List II Medium C#, Java ✔️
83 Remove Duplicates from Sorted List Easy C#, Java, Python ✔️
84 Largest Rectangle in Histogram Hard C# ✔️
85 Maximal Rectangle Hard ➖
86 Partition List Medium C#, Java, Python ✔️
87 Scramble String Hard ➖
88 Merge Sorted Array Easy C#, Java, Python ✔️
89 Gray Code Medium C#, Java ✔️
90 Subsets II Medium C#, Java, Python ✔️
91 Decode Ways Medium C#, Java, Python ✔️
92 Reverse Linked List II Medium C#, Java, Python ✔️
93 Restore IP Addresses Medium C#, Java ✔️
94 Binary Tree Inorder Traversal Easy C#, Java ✔️
95 Unique Binary Search Trees II Medium ➖
96 Unique Binary Search Trees Medium C# ✔️
97 Interleaving String Medium C# ✔️
98 Validate Binary Search Tree Medium C#, Java, Python ✔️
99 Recover Binary Search Tree Medium C# ✔️
100 Same Tree Easy C#, Java, JS ✔️
101 Symmetric Tree Easy C#, Java, Python ✔️
102 Binary Tree Level Order Traversal Medium C#, Java, Python ✔️
103 Binary Tree Zigzag Level Order Traversal Medium C#, Java ✔️
104 Maximum Depth of Binary Tree Easy C#, Java, Python ✔️
105 Construct Binary Tree from Preorder and Inorder Traversal Medium C#, Java ✔️
106 Construct Binary Tree from Inorder and Postorder Traversal Medium C# ✔️
107 Binary Tree Level Order Traversal II Medium C#, Java ✔️
108 Convert Sorted Array to Binary Search Tree Easy C#, Java, Python ✔️
109 Convert Sorted List to Binary Search Tree Medium C#, Java ✔️
110 Balanced Binary Tree Easy C#, Java, Python ✔️
111 Minimum Depth of Binary Tree Easy C#, Java ✔️
112 Path Sum Easy C#, Java, Python ✔️
113 Path Sum II Medium C#, Java, Python ✔️
114 Flatten Binary Tree to Linked List Medium C#, Java ✔️
115 Distinct Subsequences Hard ➖
116 Populating Next Right Pointers in Each Node Medium C# ✔️
117 Populating Next Right Pointers in Each Node II Medium C# ✔️
118 Pascal's Triangle Easy C#, Java, Python ✔️
119 Pascal's Triangle II Easy C# ✔️
120 Triangle Medium C#, Java ✔️
121 Best Time to Buy and Sell Stock Easy C#, Java ✔️
122 Best Time to Buy and Sell Stock II Easy C#, Java ✔️
123 Best Time to Buy and Sell Stock III Hard C#, Java ✔️
124 Binary Tree Maximum Path Sum Hard C# ✔️
125 Valid Palindrome Easy C#, JS ✔️
126 Word Ladder II Hard 〽️
127 Word Ladder Hard C# ✔️
128 Longest Consecutive Sequence Medium C# ✔️
129 Sum Root to Leaf Numbers Medium C#, Java ✔️
130 Surrounded Regions Medium C#, Java ✔️
131 Palindrome Partitioning Medium C#, Java ✔️
132 Palindrome Partitioning II Hard C# ✔️
133 Clone Graph Medium C# ✔️
134 Gas Station Medium C#, Java ✔️
135 Candy Hard C#, Java, Python ✔️
136 Single Number Easy C# ✔️
137 Single Number II Medium C#, Java ✔️
138 Copy List with Random Pointer Medium C#, Java ✔️
139 Word Break Medium C#, Java ✔️
140 Word Break II Hard ➖
141 Linked List Cycle Easy C#, Java, Python ✔️
142 Linked List Cycle II Medium C#, Java, Python ✔️
143 Reorder List Medium C#, Java, Python ✔️
144 Binary Tree Preorder Traversal Easy C#, Java ✔️
145 Binary Tree Postorder Traversal Easy C#, Java ✔️
146 LRU Cache Medium C# ✔️
147 Insertion Sort List Medium C#, Java ✔️
148 Sort List Medium C#, Java ✔️
149 Max Points on a Line Hard C# ✔️
150 Evaluate Reverse Polish Notation Medium C#, Java ✔️
151 Reverse Words in a String Medium C#, Java, Python ✔️
152 Maximum Product Subarray Medium C# ✔️
153 Find Minimum in Rotated Sorted Array Medium C#, Java ✔️
154 Find Minimum in Rotated Sorted Array II Hard C# ✔️
155 Min Stack Easy C#, Java ✔️
156 Binary Tree Upside Down Medium ➖
157 Read N Characters Given Read4 Easy C# ✔️
158 Read N Characters Given Read4 II - Call multiple times Hard ➖
159 Longest Substring with At Most Two Distinct Characters Medium C# ✔️
160 Intersection of Two Linked Lists Easy C#, Java ✔️
161 One Edit Distance Medium C#, Java ✔️
162 Find Peak Element Medium C#, Java ✔️
163 Missing Ranges Easy C# ✔️
164 Maximum Gap Hard C# ✔️
165 Compare Version Numbers Medium C# ✔️
166 Fraction to Recurring Decimal Medium ➖
167 Two Sum II - Input array is sorted Easy C# ✔️
168 Excel Sheet Column Title Easy C#, Java ✔️
169 Majority Element Easy C#, Java ✔️
170 Two Sum III - Data structure design Easy C# ✔️
171 Excel Sheet Column Number Easy C# ✔️
172 Factorial Trailing Zeroes Easy C# ✔️
173 Binary Search Tree Iterator Medium C#, Java ✔️
174 Dungeon Game Hard C#, Java, Python ✔️
175 Combine Two Tables Easy MySQL, SQLServer ✔️
176 Second Highest Salary Easy MySQL, SQLServer ✔️
177 Nth Highest Salary Medium MySQL, SQLServer ✔️
178 Rank Scores Medium MySQL, SQLServer ✔️
179 Largest Number Medium C#, Java ✔️
180 Consecutive Numbers Medium MySQL, SQLServer ✔️
181 Employees Earning More Than Their Managers Easy MySQL, SQLServer ✔️
182 Duplicate Emails Easy MySQL, SQLServer ✔️
183 Customers Who Never Order Easy MySQL, SQLServer ✔️
184 Department Highest Salary Medium MySQL, SQLServer ✔️
185 Department Top Three Salaries Hard SQLServer ✔️
186 Reverse Words in a String II Medium C# ✔️
187 Repeated DNA Sequences Medium C# ✔️
188 Best Time to Buy and Sell Stock IV Hard ➖
189 Rotate Array Medium C#, Java ✔️
190 Reverse Bits Easy C#, Java ✔️
191 Number of 1 Bits Easy C#, Java ✔️
192 Word Frequency Medium ➖
193 Valid Phone Numbers Easy ➖
194 Transpose File Medium ➖
195 Tenth Line Easy ➖
196 Delete Duplicate Emails Easy MySQL, SQLServer ✔️
197 Rising Temperature Easy MySQL, SQLServer ✔️
198 House Robber Medium C#, Java ✔️
199 Binary Tree Right Side View Medium C#, Java ✔️
200 Number of Islands Medium C#, Java ✔️
201 Bitwise AND of Numbers Range Medium C#, Java ✔️
202 Happy Number Easy C#, Java ✔️
203 Remove Linked List Elements Easy C#, Java, Python ✔️
204 Count Primes Easy C#, Java ✔️
205 Isomorphic Strings Easy C#, Java ✔️
206 Reverse Linked List Easy C#, Java, Python ✔️
207 Course Schedule Medium C#, Java ✔️
208 Implement Trie (Prefix Tree) Medium C#, Java, Python ✔️
209 Minimum Size Subarray Sum Medium C# ✔️
210 Course Schedule II Medium C# ✔️
211 Design Add and Search Words Data Structure Medium C# ✔️
212 Word Search II Hard C# ✔️
213 House Robber II Medium C#, Java ✔️
214 Shortest Palindrome Hard ➖
215 Kth Largest Element in an Array Medium C#, Java ✔️
216 Combination Sum III Medium C# ✔️
217 Contains Duplicate Easy C# ✔️
218 The Skyline Problem Hard ➖
219 Contains Duplicate II Easy C#, Java ✔️
220 Contains Duplicate III Medium C# ✔️
221 Maximal Square Medium C#, Java ✔️
222 Count Complete Tree Nodes Medium C#, Java ✔️
223 Rectangle Area Medium C# ✔️
224 Basic Calculator Hard C#, Java ✔️
225 Implement Stack using Queues Easy C# ✔️
226 Invert Binary Tree Easy C#, Java, Python, JS ✔️
227 Basic Calculator II Medium C# ✔️
228 Summary Ranges Easy C# ✔️
229 Majority Element II Medium C# ✔️
230 Kth Smallest Element in a BST Medium C#, Java ✔️
231 Power of Two Easy C#, Java ✔️
232 Implement Queue using Stacks Easy C#, Java, Python ✔️
233 Number of Digit One Hard ➖
234 Palindrome Linked List Easy C#, Java ✔️
235 Lowest Common Ancestor of a Binary Search Tree Easy C#, Java, Python ✔️
236 Lowest Common Ancestor of a Binary Tree Medium C#, Java ✔️
237 Delete Node in a Linked List Easy C#, Java ✔️
238 Product of Array Except Self Medium C#, Java ✔️
239 Sliding Window Maximum Hard C# ✔️
240 Search a 2D Matrix II Medium C#, Java ✔️
241 Different Ways to Add Parentheses Medium C# ✔️
242 Valid Anagram Easy C#, Java ✔️
243 Shortest Word Distance Easy C# ✔️
244 Shortest Word Distance II Medium C#, Java ✔️
245 Shortest Word Distance III Medium C# ✔️
246 Strobogrammatic Number Easy C#, Java ✔️
247 Strobogrammatic Number II Medium C# ✔️
248 Strobogrammatic Number III Hard ➖
249 Group Shifted Strings Medium C# ✔️
250 Count Univalue Subtrees Medium C# ✔️
251 Flatten 2D Vector Medium C# ✔️
252 Meeting Rooms Easy C# ✔️
253 Meeting Rooms II Medium C# ✔️
254 Factor Combinations Medium C# ✔️
255 Verify Preorder Sequence in Binary Search Tree Medium ➖
256 Paint House Medium C#, Java ✔️
257 Binary Tree Paths Easy C#, Java ✔️
258 Add Digits Easy C# ✔️
259 3Sum Smaller Medium C# ✔️
260 Single Number III Medium C# ✔️
261 Graph Valid Tree Medium C# ✔️
262 Trips and Users Hard MySQL, SQLServer ✔️
263 Ugly Number Easy C#, Java ✔️
264 Ugly Number II Medium C#, Java ✔️
265 Paint House II Hard ➖
266 Palindrome Permutation Easy C#, Java ✔️
267 Palindrome Permutation II Medium ➖
268 Missing Number Easy C# ✔️
269 Alien Dictionary Hard ➖
270 Closest Binary Search Tree Value Easy C#, Java ✔️
271 Encode and Decode Strings Medium C# ✔️
272 Closest Binary Search Tree Value II Hard Java ✔️
273 Integer to English Words Hard ➖
274 H-Index Medium C#, Java ✔️
275 H-Index II Medium C#, Java ✔️
276 Paint Fence Medium C# ✔️
277 Find the Celebrity Medium C# ✔️
278 First Bad Version Easy C#, Java ✔️
279 Perfect Squares Medium C#, Java, Python ✔️
280 Wiggle Sort Medium C# ✔️
281 Zigzag Iterator Medium C# ✔️
282 Expression Add Operators Hard ➖
283 Move Zeroes Easy C# ✔️
284 Peeking Iterator Medium C#, Java ✔️
285 Inorder Successor in BST Medium C#, Java ✔️
286 Walls and Gates Medium C# ✔️
287 Find the Duplicate Number Medium C#, Java ✔️
288 Unique Word Abbreviation Medium C# ✔️
289 Game of Life Medium C#, Java ✔️
290 Word Pattern Easy C# ✔️
291 Word Pattern II Medium ➖
292 Nim Game Easy C# ✔️
293 Flip Game Easy C# ✔️
294 Flip Game II Medium ➖
295 Find Median from Data Stream Hard C#, Java ✔️
296 Best Meeting Point Hard C# ✔️
297 Serialize and Deserialize Binary Tree Hard C#, Java ✔️
298 Binary Tree Longest Consecutive Sequence Medium C# ✔️
299 Bulls and Cows Medium C#, Java ✔️
300 Longest Increasing Subsequence Medium C# ✔️
301 Remove Invalid Parentheses Hard ➖
302 Smallest Rectangle Enclosing Black Pixels Hard ➖
303 Range Sum Query - Immutable Easy C#, Java, Python ✔️
304 Range Sum Query 2D - Immutable Medium C#, Java ✔️
305 Number of Islands II Hard ➖
306 Additive Number Medium ➖
307 Range Sum Query - Mutable Medium C# ✔️
308 Range Sum Query 2D - Mutable Hard ➖
309 Best Time to Buy and Sell Stock with Cooldown Medium C#, Java ✔️
310 Minimum Height Trees Medium C# ✔️
311 Sparse Matrix Multiplication Medium C# ✔️
312 Burst Balloons Hard ➖
313 Super Ugly Number Medium ➖
314 Binary Tree Vertical Order Traversal Medium C# ✔️
315 Count of Smaller Numbers After Self Hard C#, Java ✔️
316 Remove Duplicate Letters Medium C#, Java ✔️
317 Shortest Distance from All Buildings Hard C# ✔️
318 Maximum Product of Word Lengths Medium C# ✔️
319 Bulb Switcher Medium C# ✔️
320 Generalized Abbreviation Medium C# ✔️
321 Create Maximum Number Hard ➖
322 Coin Change Medium C#, Java ✔️
323 Number of Connected Components in an Undirected Graph Medium C#, Java ✔️
324 Wiggle Sort II Medium ➖
325 Maximum Size Subarray Sum Equals k Medium C# ✔️
326 Power of Three Easy C#, Java ✔️
327 Count of Range Sum Hard ➖
328 Odd Even Linked List Medium C#, Java ✔️
329 Longest Increasing Path in a Matrix Hard C# ✔️
330 Patching Array Hard ➖
331 Verify Preorder Serialization of a Binary Tree Medium C# ✔️
332 Reconstruct Itinerary Medium ➖
333 Largest BST Subtree Medium C# ✔️
334 Increasing Triplet Subsequence Medium C# ✔️
335 Self Crossing Hard ➖
336 Palindrome Pairs Hard C# ✔️
337 House Robber III Medium C# ✔️
338 Counting Bits Easy C#, Java ✔️
339 Nested List Weight Sum Medium C# ✔️
340 Longest Substring with At Most K Distinct Characters Medium C# ✔️
341 Flatten Nested List Iterator Medium C#, Java ✔️
342 Power of Four Easy C#, Java ✔️
343 Integer Break Medium C#, Java ✔️
344 Reverse String Easy C# ✔️
345 Reverse Vowels of a String Easy C#, Java ✔️
346 Moving Average from Data Stream Easy C#, Java ✔️
347 Top K Frequent Elements Medium C#, Java ✔️
348 Design Tic-Tac-Toe Medium C# ✔️
349 Intersection of Two Arrays Easy C# ✔️
350 Intersection of Two Arrays II Easy C#, Java ✔️
351 Android Unlock Patterns Medium ➖
352 Data Stream as Disjoint Intervals Hard ➖
353 Design Snake Game Medium C# ✔️
354 Russian Doll Envelopes Hard C# ✔️
355 Design Twitter Medium C#, Java ✔️
356 Line Reflection Medium C# ✔️
357 Count Numbers with Unique Digits Medium C# ✔️
358 Rearrange String k Distance Apart Hard ➖
359 Logger Rate Limiter Easy C#, Java ✔️
360 Sort Transformed Array Medium C# ✔️
361 Bomb Enemy Medium C# ✔️
362 Design Hit Counter Medium C# ✔️
363 Max Sum of Rectangle No Larger Than K Hard C#, Java ✔️
364 Nested List Weight Sum II Medium C# ✔️
365 Water and Jug Problem Medium C# ✔️
366 Find Leaves of Binary Tree Medium C#, Java ✔️
367 Valid Perfect Square Easy C# ✔️
368 Largest Divisible Subset Medium C#, Java ✔️
369 Plus One Linked List Medium C# ✔️
370 Range Addition Medium C#, Java ✔️
371 Sum of Two Integers Medium C#, Java ✔️
372 Super Pow Medium ➖
373 Find K Pairs with Smallest Sums Medium C# ✔️
374 Guess Number Higher or Lower Easy C#, Java, Python ✔️
375 Guess Number Higher or Lower II Medium ➖
376 Wiggle Subsequence Medium C#, Java ✔️
377 Combination Sum IV Medium C# ✔️
378 Kth Smallest Element in a Sorted Matrix Medium C#, Java ✔️
379 Design Phone Directory Medium C# ✔️
380 Insert Delete GetRandom O(1) Medium C#, Java ✔️
381 Insert Delete GetRandom O(1) - Duplicates allowed Hard ➖
382 Linked List Random Node Medium C# ✔️
383 Ransom Note Easy C#, Java ✔️
384 Shuffle an Array Medium C#, Java ✔️
385 Mini Parser Medium ➖
386 Lexicographical Numbers Medium ➖
387 First Unique Character in a String Easy C#, Java ✔️
388 Longest Absolute File Path Medium ➖
389 Find the Difference Easy C# ✔️
390 Elimination Game Medium C# ✔️
391 Perfect Rectangle Hard ➖
392 Is Subsequence Easy C# ✔️
393 UTF-8 Validation Medium ➖
394 Decode String Medium C# ✔️
395 Longest Substring with At Least K Repeating Characters Medium C# ✔️
396 Rotate Function Medium C# ✔️
397 Integer Replacement Medium C# ✔️
398 Random Pick Index Medium C# ✔️
399 Evaluate Division Medium C# ✔️
400 Nth Digit Medium ➖
401 Binary Watch Easy C# ✔️
402 Remove K Digits Medium C# ✔️
403 Frog Jump Hard C#, Java ✔️
404 Sum of Left Leaves Easy C#, Java ✔️
405 Convert a Number to Hexadecimal Easy C# ✔️
406 Queue Reconstruction by Height Medium C#, Java ✔️
407 Trapping Rain Water II Hard ➖
408 Valid Word Abbreviation Easy C# ✔️
409 Longest Palindrome Easy C# ✔️
410 Split Array Largest Sum Hard ➖
411 Minimum Unique Word Abbreviation Hard ➖
412 Fizz Buzz Easy C# ✔️
413 Arithmetic Slices Medium C# ✔️
414 Third Maximum Number Easy C# ✔️
415 Add Strings Easy C#, Java ✔️
416 Partition Equal Subset Sum Medium C# ✔️
417 Pacific Atlantic Water Flow Medium C#, Java ✔️
418 Sentence Screen Fitting Medium C# ✔️
419 Battleships in a Board Medium C# ✔️
420 Strong Password Checker Hard ➖
421 Maximum XOR of Two Numbers in an Array Medium C# ✔️
422 Valid Word Square Easy C# ✔️
423 Reconstruct Original Digits from English Medium C# ✔️
424 Longest Repeating Character Replacement Medium C# ✔️
425 Word Squares Hard ➖
426 Convert Binary Search Tree to Sorted Doubly Linked List Medium C# ✔️
427 Construct Quad Tree Medium ➖
428 Serialize and Deserialize N-ary Tree Hard ➖
429 N-ary Tree Level Order Traversal Medium C#, Java, Python ✔️
430 Flatten a Multilevel Doubly Linked List Medium C# ✔️
431 Encode N-ary Tree to Binary Tree Hard ➖
432 All O one Data Structure Hard ➖
433 Minimum Genetic Mutation Medium C# ✔️
434 Number of Segments in a String Easy C# ✔️
435 Non-overlapping Intervals Medium C#, Java, Python ✔️
436 Find Right Interval Medium C#, Java ✔️
437 Path Sum III Medium C#, Java, Python ✔️
438 Find All Anagrams in a String Medium C# ✔️
439 Ternary Expression Parser Medium C#, Java ✔️
440 K-th Smallest in Lexicographical Order Hard ➖
441 Arranging Coins Easy C# ✔️
442 Find All Duplicates in an Array Medium C#, Java ✔️
443 String Compression Medium C# ✔️
444 Sequence Reconstruction Medium ➖
445 Add Two Numbers II Medium C#, Java ✔️
446 Arithmetic Slices II - Subsequence Hard ➖
447 Number of Boomerangs Medium C# ✔️
448 Find All Numbers Disappeared in an Array Easy C# ✔️
449 Serialize and Deserialize BST Medium C# ✔️
450 Delete Node in a BST Medium C# ✔️
451 Sort Characters By Frequency Medium C#, Java ✔️
452 Minimum Number of Arrows to Burst Balloons Medium C#, Java ✔️
453 Minimum Moves to Equal Array Elements Easy C# ✔️
454 4Sum II Medium C# ✔️
455 Assign Cookies Easy C# ✔️
456 132 Pattern Medium C# ✔️
457 Circular Array Loop Medium C#, Java ✔️
458 Poor Pigs Hard ➖
459 Repeated Substring Pattern Easy C# ✔️
460 LFU Cache Hard ➖
461 Hamming Distance Easy C#, Java ✔️
462 Minimum Moves to Equal Array Elements II Medium C#, Java ✔️
463 Island Perimeter Easy C#, Java ✔️
464 Can I Win Medium ➖
465 Optimal Account Balancing Hard ➖
466 Count The Repetitions Hard ➖
467 Unique Substrings in Wraparound String Medium ➖
468 Validate IP Address Medium C# ✔️
469 Convex Polygon Medium ➖
470 Implement Rand10() Using Rand7() Medium C# ✔️
471 Encode String with Shortest Length Hard ➖
472 Concatenated Words Hard ➖
473 Matchsticks to Square Medium C#, Java ✔️
474 Ones and Zeroes Medium C# ✔️
475 Heaters Medium C# ✔️
476 Number Complement Easy C# ✔️
477 Total Hamming Distance Medium C#, Java ✔️
478 Generate Random Point in a Circle Medium C#, Java ✔️
479 Largest Palindrome Product Hard ➖
480 Sliding Window Median Hard ➖
481 Magical String Medium C# ✔️
482 License Key Formatting Easy C# ✔️
483 Smallest Good Base Hard ➖
484 Find Permutation Medium C# ✔️
485 Max Consecutive Ones Easy C#, Java ✔️
486 Predict the Winner Medium ➖
487 Max Consecutive Ones II Medium C# ✔️
488 Zuma Game Hard C# ✔️
489 Robot Room Cleaner Hard ➖
490 The Maze Medium C# ✔️
491 Increasing Subsequences Medium C# ✔️
492 Construct the Rectangle Easy C# ✔️
493 Reverse Pairs Hard ➖
494 Target Sum Medium C#, Java ✔️
495 Teemo Attacking Easy C# ✔️
496 Next Greater Element I Easy C#, Java, Python ✔️
497 Random Point in Non-overlapping Rectangles Medium C# ✔️
498 Diagonal Traverse Medium C#, Java ✔️
499 The Maze III Hard ➖
500 Keyboard Row Easy C# ✔️
501 Find Mode in Binary Search Tree Easy C#, Java ✔️
502 IPO Hard ➖
503 Next Greater Element II Medium C#, Java, Python ✔️
504 Base 7 Easy C# ✔️
505 The Maze II Medium C#, Java ✔️
506 Relative Ranks Easy C#, Java ✔️
507 Perfect Number Easy C# ✔️
508 Most Frequent Subtree Sum Medium C#, Java ✔️
509 Fibonacci Number Easy C#, Java ✔️
510 Inorder Successor in BST II Medium C# ✔️
511 Game Play Analysis I Easy MySQL, SQLServer ✔️
512 Game Play Analysis II Easy MySQL, SQLServer ✔️
513 Find Bottom Left Tree Value Medium C# ✔️
514 Freedom Trail Hard ➖
515 Find Largest Value in Each Tree Row Medium C#, Java ✔️
516 Longest Palindromic Subsequence Medium C# ✔️
517 Super Washing Machines Hard ➖
518 Coin Change 2 Medium C# ✔️
519 Random Flip Matrix Medium ➖
520 Detect Capital Easy C# ✔️
521 Longest Uncommon Subsequence I Easy C# ✔️
522 Longest Uncommon Subsequence II Medium ➖
523 Continuous Subarray Sum Medium C# ✔️
524 Longest Word in Dictionary through Deleting Medium C#, Java ✔️
525 Contiguous Array Medium C#, Java ✔️
526 Beautiful Arrangement Medium C# ✔️
527 Word Abbreviation Hard ➖
528 Random Pick with Weight Medium C# ✔️
529 Minesweeper Medium C#, Java ✔️
530 Minimum Absolute Difference in BST Easy C#, Java ✔️
531 Lonely Pixel I Medium C# ✔️
532 K-diff Pairs in an Array Medium C# ✔️
533 Lonely Pixel II Medium ➖
534 Game Play Analysis III Medium MySQL, SQLServer ✔️
535 Encode and Decode TinyURL Medium C#, Java ✔️
536 Construct Binary Tree from String Medium C#, Java ✔️
537 Complex Number Multiplication Medium C#, Java ✔️
538 Convert BST to Greater Tree Medium C# ✔️
539 Minimum Time Difference Medium C# ✔️
540 Single Element in a Sorted Array Medium C#, Java ✔️
541 Reverse String II Easy C# ✔️
542 01 Matrix Medium C#, Java ✔️
543 Diameter of Binary Tree Easy C#, Java, Python ✔️
544 Output Contest Matches Medium C# ✔️
545 Boundary of Binary Tree Medium C# ✔️
546 Remove Boxes Hard C# ✔️
547 Number of Provinces Medium C#, Java ✔️
548 Split Array with Equal Sum Medium ➖
549 Binary Tree Longest Consecutive Sequence II Medium ➖
550 Game Play Analysis IV Medium MySQL, SQLServer ✔️
551 Student Attendance Record I Easy C# ✔️
552 Student Attendance Record II Hard ➖
553 Optimal Division Medium C# ✔️
554 Brick Wall Medium C#, Java ✔️
555 Split Concatenated Strings Medium ➖
556 Next Greater Element III Medium C# ✔️
557 Reverse Words in a String III Easy C# ✔️
558 Logical OR of Two Binary Grids Represented as Quad-Trees Medium ➖
559 Maximum Depth of N-ary Tree Easy C#, Java ✔️
560 Subarray Sum Equals K Medium C# ✔️
561 Array Partition I Easy C# ✔️
562 Longest Line of Consecutive One in Matrix Medium C# ✔️
563 Binary Tree Tilt Easy C#, Java ✔️
564 Find the Closest Palindrome Hard ➖
565 Array Nesting Medium C#, Java ✔️
566 Reshape the Matrix Easy C#, Java, Python ✔️
567 Permutation in String Medium C# ✔️
568 Maximum Vacation Days Hard ➖
569 Median Employee Salary Hard MySQL, SQLServer ✔️
570 Managers with at Least 5 Direct Reports Medium MySQL, SQLServer ✔️
571 Find Median Given Frequency of Numbers Hard SQLServer ✔️
572 Subtree of Another Tree Easy C#, Java ✔️
573 Squirrel Simulation Medium C# ✔️
574 Winning Candidate Medium MySQL, SQLServer ✔️
575 Distribute Candies Easy C#, Java ✔️
576 Out of Boundary Paths Medium C# ✔️
577 Employee Bonus Easy MySQL, SQLServer ✔️
578 Get Highest Answer Rate Question Medium MySQL, SQLServer ✔️
579 Find Cumulative Salary of an Employee Hard MySQL, SQLServer ✔️
580 Count Student Number in Departments Medium MySQL, SQLServer ✔️
581 Shortest Unsorted Continuous Subarray Medium C#, Java, Python ✔️
582 Kill Process Medium C#, Java ✔️
583 Delete Operation for Two Strings Medium C#, Java ✔️
584 Find Customer Referee Easy MySQL, SQLServer ✔️
585 Investments in 2016 Medium MySQL, SQLServer ✔️
586 Customer Placing the Largest Number of Orders Easy MySQL, SQLServer ✔️
587 Erect the Fence Hard ➖
588 Design In-Memory File System Hard C# ✔️
589 N-ary Tree Preorder Traversal Easy C#, Java ✔️
590 N-ary Tree Postorder Traversal Easy C#, Java ✔️
591 Tag Validator Hard ➖
592 Fraction Addition and Subtraction Medium C# ✔️
593 Valid Square Medium C# ✔️
594 Longest Harmonious Subsequence Easy C#, Java ✔️
595 Big Countries Easy MySQL, SQLServer ✔️
596 Classes More Than 5 Students Easy MySQL, SQLServer ✔️
597 Friend Requests I: Overall Acceptance Rate Easy MySQL, SQLServer ✔️
598 Range Addition II Easy C# ✔️
599 Minimum Index Sum of Two Lists Easy C# ✔️
600 Non-negative Integers without Consecutive Ones Hard ➖
601 Human Traffic of Stadium Hard MySQL, SQLServer ✔️
602 Friend Requests II: Who Has the Most Friends Medium MySQL, SQLServer ✔️
603 Consecutive Available Seats Easy MySQL, SQLServer ✔️
604 Design Compressed String Iterator Easy C# ✔️
605 Can Place Flowers Easy C# ✔️
606 Construct String from Binary Tree Easy C#, Java ✔️
607 Sales Person Easy MySQL, SQLServer ✔️
608 Tree Node Medium MySQL, SQLServer ✔️
609 Find Duplicate File in System Medium C# ✔️
610 Triangle Judgement Easy MySQL, SQLServer ✔️
611 Valid Triangle Number Medium C#, Java, Python ✔️
612 Shortest Distance in a Plane Medium MySQL, SQLServer ✔️
613 Shortest Distance in a Line Easy MySQL, SQLServer ✔️
614 Second Degree Follower Medium MySQL, SQLServer ✔️
615 Average Salary: Departments VS Company Hard MySQL, SQLServer ✔️
616 Add Bold Tag in String Medium C# ✔️
617 Merge Two Binary Trees Easy C#, Java ✔️
618 Students Report By Geography Hard MySQL, SQLServer ✔️
619 Biggest Single Number Easy MySQL, SQLServer ✔️
620 Not Boring Movies Easy MySQL, SQLServer ✔️
621 Task Scheduler Medium C#, Java ✔️
622 Design Circular Queue Medium C#, Java ✔️
623 Add One Row to Tree Medium C#, Java ✔️
624 Maximum Distance in Arrays Medium C# ✔️
625 Minimum Factorization Medium C# ✔️
626 Exchange Seats Medium MySQL, SQLServer ✔️
627 Swap Salary Easy MySQL, SQLServer ✔️
628 Maximum Product of Three Numbers Easy C#, Java ✔️
629 K Inverse Pairs Array Hard ➖
630 Course Schedule III Hard Java ✔️
631 Design Excel Sum Formula Hard ➖
632 Smallest Range Covering Elements from K Lists Hard ➖
633 Sum of Square Numbers Medium C#, Java ✔️
634 Find the Derangement of An Array Medium ➖
635 Design Log Storage System Medium C# ✔️
636 Exclusive Time of Functions Medium ➖
637 Average of Levels in Binary Tree Easy C#, Java ✔️
638 Shopping Offers Medium ➖
639 Decode Ways II Hard C# ✔️
640 Solve the Equation Medium C# ✔️
641 Design Circular Deque Medium C# ✔️
642 Design Search Autocomplete System Hard ➖
643 Maximum Average Subarray I Easy C# ✔️
644 Maximum Average Subarray II Hard ➖
645 Set Mismatch Easy C#, Java ✔️
646 Maximum Length of Pair Chain Medium C# ✔️
647 Palindromic Substrings Medium C#, Java ✔️
648 Replace Words Medium C# ✔️
649 Dota2 Senate Medium C# ✔️
650 2 Keys Keyboard Medium C# ✔️
651 4 Keys Keyboard Medium ➖
652 Find Duplicate Subtrees Medium C# ✔️
653 Two Sum IV - Input is a BST Easy C#, Java ✔️
654 Maximum Binary Tree Medium C#, Java ✔️
655 Print Binary Tree Medium C# ✔️
656 Coin Path Hard ➖
657 Robot Return to Origin Easy C# ✔️
658 Find K Closest Elements Medium C#, Java ✔️
659 Split Array into Consecutive Subsequences Medium ➖
660 Remove 9 Hard ➖
661 Image Smoother Easy C# ✔️
662 Maximum Width of Binary Tree Medium C# ✔️
663 Equal Tree Partition Medium C#, Java ✔️
664 Strange Printer Hard C# ✔️
665 Non-decreasing Array Medium C#, Java ✔️
666 Path Sum IV Medium C# ✔️
667 Beautiful Arrangement II Medium C#, Java ✔️
668 Kth Smallest Number in Multiplication Table Hard ➖
669 Trim a Binary Search Tree Medium C#, Java ✔️
670 Maximum Swap Medium C# ✔️
671 Second Minimum Node In a Binary Tree Easy C#, Java, Python ✔️
672 Bulb Switcher II Medium ➖
673 Number of Longest Increasing Subsequence Medium ➖
674 Longest Continuous Increasing Subsequence Easy C# ✔️
675 Cut Off Trees for Golf Event Hard ➖
676 Implement Magic Dictionary Medium C# ✔️
677 Map Sum Pairs Medium C#, Java ✔️
678 Valid Parenthesis String Medium C# ✔️
679 24 Game Hard ➖
680 Valid Palindrome II Easy C# ✔️
681 Next Closest Time Medium C# ✔️
682 Baseball Game Easy C#, Java ✔️
683 K Empty Slots Hard ➖
684 Redundant Connection Medium C#, Java ✔️
685 Redundant Connection II Hard ➖
686 Repeated String Match Medium C# ✔️
687 Longest Univalue Path Medium C# ✔️
688 Knight Probability in Chessboard Medium C# ✔️
689 Maximum Sum of 3 Non-Overlapping Subarrays Hard ➖
690 Employee Importance Easy C#, Java ✔️
691 Stickers to Spell Word Hard ➖
692 Top K Frequent Words Medium C#, Java ✔️
693 Binary Number with Alternating Bits Easy C# ✔️
694 Number of Distinct Islands Medium C#, Java ✔️
695 Max Area of Island Medium C#, Java ✔️
696 Count Binary Substrings Easy C#, Java ✔️
697 Degree of an Array Easy C# ✔️
698 Partition to K Equal Sum Subsets Medium C# ✔️
699 Falling Squares Hard ➖
700 Search in a Binary Search Tree Easy C#, Java, Python ✔️
701 Insert into a Binary Search Tree Medium C#, Java, Python ✔️
702 Search in a Sorted Array of Unknown Size Medium C# ✔️
703 Kth Largest Element in a Stream Easy C#, Java ✔️
704 Binary Search Easy C# ✔️
705 Design HashSet Easy C#, Java ✔️
706 Design HashMap Easy C#, Java ✔️
707 Design Linked List Medium C# ✔️
708 Insert into a Sorted Circular Linked List Medium C# ✔️
709 To Lower Case Easy C# ✔️
710 Random Pick with Blacklist Hard ➖
711 Number of Distinct Islands II Hard ➖
712 Minimum ASCII Delete Sum for Two Strings Medium C# ✔️
713 Subarray Product Less Than K Medium C# ✔️
714 Best Time to Buy and Sell Stock with Transaction Fee Medium C#, Java ✔️
715 Range Module Hard ➖
716 Max Stack Easy C# ✔️
717 1-bit and 2-bit Characters Easy C# ✔️
718 Maximum Length of Repeated Subarray Medium C# ✔️
719 Find K-th Smallest Pair Distance Hard ➖
720 Longest Word in Dictionary Medium C# ✔️
721 Accounts Merge Medium C# ✔️
722 Remove Comments Medium ➖
723 Candy Crush Medium C# ✔️
724 Find Pivot Index Easy C# ✔️
725 Split Linked List in Parts Medium C# ✔️
726 Number of Atoms Hard ➖
727 Minimum Window Subsequence Hard ➖
728 Self Dividing Numbers Easy C# ✔️
729 My Calendar I Medium C#, Java ✔️
730 Count Different Palindromic Subsequences Hard ➖
731 My Calendar II Medium ➖
732 My Calendar III Hard ➖
733 Flood Fill Easy C#, Java ✔️
734 Sentence Similarity Easy C# ✔️
735 Asteroid Collision Medium C#, Java ✔️
736 Parse Lisp Expression Hard ➖
737 Sentence Similarity II Medium C# ✔️
738 Monotone Increasing Digits Medium C# ✔️
739 Daily Temperatures Medium C#, Java ✔️
740 Delete and Earn Medium C#, Java ✔️
741 Cherry Pickup Hard ➖
742 Closest Leaf in a Binary Tree Medium C# ✔️
743 Network Delay Time Medium C# ✔️
744 Find Smallest Letter Greater Than Target Easy C# ✔️
745 Prefix and Suffix Search Hard C# ✔️
746 Min Cost Climbing Stairs Easy C#, Java ✔️
747 Largest Number At Least Twice of Others Easy C# ✔️
748 Shortest Completing Word Easy C# ✔️
749 Contain Virus Hard ➖
750 Number Of Corner Rectangles Medium C# ✔️
751 IP to CIDR Medium ➖
752 Open the Lock Medium C#, Java ✔️
753 Cracking the Safe Hard ➖
754 Reach a Number Medium C# ✔️
755 Pour Water Medium ➖
756 Pyramid Transition Matrix Medium ➖
757 Set Intersection Size At Least Two Hard ➖
758 Bold Words in String Medium C# ✔️
759 Employee Free Time Hard C# ✔️
760 Find Anagram Mappings Easy C# ✔️
761 Special Binary String Hard ➖
762 Prime Number of Set Bits in Binary Representation Easy C# ✔️
763 Partition Labels Medium C# ✔️
764 Largest Plus Sign Medium ➖
765 Couples Holding Hands Hard ➖
766 Toeplitz Matrix Easy C# ✔️
767 Reorganize String Medium C#, Java ✔️
768 Max Chunks To Make Sorted II Hard ➖
769 Max Chunks To Make Sorted Medium C# ✔️
770 Basic Calculator IV Hard ➖
771 Jewels and Stones Easy C# ✔️
772 Basic Calculator III Hard ➖
773 Sliding Puzzle Hard C# ✔️
774 Minimize Max Distance to Gas Station Hard ➖
775 Global and Local Inversions Medium C#, Java ✔️
776 Split BST Medium C# ✔️
777 Swap Adjacent in LR String Medium ➖
778 Swim in Rising Water Hard Java ✔️
779 K-th Symbol in Grammar Medium C# ✔️
780 Reaching Points Hard ➖
781 Rabbits in Forest Medium C#, Java ✔️
782 Transform to Chessboard Hard ➖
783 Minimum Distance Between BST Nodes Easy C# ✔️
784 Letter Case Permutation Medium C#, Java ✔️
785 Is Graph Bipartite? Medium C# ✔️
786 K-th Smallest Prime Fraction Hard ➖
787 Cheapest Flights Within K Stops Medium C# ✔️
788 Rotated Digits Easy C# ✔️
789 Escape The Ghosts Medium C# ✔️
790 Domino and Tromino Tiling Medium ➖
791 Custom Sort String Medium C# ✔️
792 Number of Matching Subsequences Medium C#, Java ✔️
793 Preimage Size of Factorial Zeroes Function Hard ➖
794 Valid Tic-Tac-Toe State Medium C# ✔️
795 Number of Subarrays with Bounded Maximum Medium C#, Java ✔️
796 Rotate String Easy C# ✔️
797 All Paths From Source to Target Medium C# ✔️
798 Smallest Rotation with Highest Score Hard ➖
799 Champagne Tower Medium ➖
800 Similar RGB Color Easy C# ✔️
801 Minimum Swaps To Make Sequences Increasing Hard ➖
802 Find Eventual Safe States Medium C#, Java ✔️
803 Bricks Falling When Hit Hard
804 Unique Morse Code Words Easy C# ✔️
805 Split Array With Same Average Hard ➖
806 Number of Lines To Write String Easy C# ✔️
807 Max Increase to Keep City Skyline Medium C# ✔️
808 Soup Servings Medium ➖
809 Expressive Words Medium C# ✔️
810 Chalkboard XOR Game Hard ➖
811 Subdomain Visit Count Easy C# ✔️
812 Largest Triangle Area Easy C# ✔️
813 Largest Sum of Averages Medium C# ✔️
814 Binary Tree Pruning Medium C#, Java, Python ✔️
815 Bus Routes Hard C# ✔️
816 Ambiguous Coordinates Medium C# ✔️
817 Linked List Components Medium C# ✔️
818 Race Car Hard ➖
819 Most Common Word Easy C# ✔️
820 Short Encoding of Words Medium C#, Java ✔️
821 Shortest Distance to a Character Easy C# ✔️
822 Card Flipping Game Medium ➖
823 Binary Trees With Factors Medium C# ✔️
824 Goat Latin Easy C# ✔️
825 Friends Of Appropriate Ages Medium C# ✔️
826 Most Profit Assigning Work Medium C# ✔️
827 Making A Large Island Hard C# ✔️
828 Count Unique Characters of All Substrings of a Given String Hard ➖
829 Consecutive Numbers Sum Hard C# ✔️
830 Positions of Large Groups Easy C# ✔️
831 Masking Personal Information Medium C# ✔️
832 Flipping an Image Easy C#, Java ✔️
833 Find And Replace in String Medium C# ✔️
834 Sum of Distances in Tree Hard ➖
835 Image Overlap Medium C# ✔️
836 Rectangle Overlap Easy C# ✔️
837 New 21 Game Medium ➖
838 Push Dominoes Medium C#, Java ✔️
839 Similar String Groups Hard ➖
840 Magic Squares In Grid Medium C# ✔️
841 Keys and Rooms Medium C#, Java ✔️
842 Split Array into Fibonacci Sequence Medium ➖
843 Guess the Word Hard ➖
844 Backspace String Compare Easy C# ✔️
845 Longest Mountain in Array Medium C# ✔️
846 Hand of Straights Medium C# ✔️
847 Shortest Path Visiting All Nodes Hard ➖
848 Shifting Letters Medium C#, Java ✔️
849 Maximize Distance to Closest Person Medium C# ✔️
850 Rectangle Area II Hard ➖
851 Loud and Rich Medium C# ✔️
852 Peak Index in a Mountain Array Easy C#, Java ✔️
853 Car Fleet Medium C#, Java ✔️
854 K-Similar Strings Hard ➖
855 Exam Room Medium ➖
856 Score of Parentheses Medium C#, Java ✔️
857 Minimum Cost to Hire K Workers Hard ➖
858 Mirror Reflection Medium ➖
859 Buddy Strings Easy C# ✔️
860 Lemonade Change Easy C# ✔️
861 Score After Flipping Matrix Medium C# ✔️
862 Shortest Subarray with Sum at Least K Hard ➖
863 All Nodes Distance K in Binary Tree Medium C# ✔️
864 Shortest Path to Get All Keys Hard ➖
865 Smallest Subtree with all the Deepest Nodes Medium C# ✔️
866 Prime Palindrome Medium ➖
867 Transpose Matrix Easy C# ✔️
868 Binary Gap Easy C# ✔️
869 Reordered Power of 2 Medium C#, Java ✔️
870 Advantage Shuffle Medium C#, Java ✔️
871 Minimum Number of Refueling Stops Hard Java ✔️
872 Leaf-Similar Trees Easy C#, Java ✔️
873 Length of Longest Fibonacci Subsequence Medium ➖
874 Walking Robot Simulation Easy C# ✔️
875 Koko Eating Bananas Medium C#, Java ✔️
876 Middle of the Linked List Easy C# ✔️
877 Stone Game Medium C#, Java, Python ✔️
878 Nth Magical Number Hard ➖
879 Profitable Schemes Hard ➖
880 Decoded String at Index Medium C# ✔️
881 Boats to Save People Medium C# ✔️
882 Reachable Nodes In Subdivided Graph Hard ➖
883 Projection Area of 3D Shapes Easy C# ✔️
884 Uncommon Words from Two Sentences Easy C# ✔️
885 Spiral Matrix III Medium C# ✔️
886 Possible Bipartition Medium C# ✔️
887 Super Egg Drop Hard ➖
888 Fair Candy Swap Easy C#, Java ✔️
889 Construct Binary Tree from Preorder and Postorder Traversal Medium C# ✔️
890 Find and Replace Pattern Medium C# ✔️
891 Sum of Subsequence Widths Hard ➖
892 Surface Area of 3D Shapes Easy C# ✔️
893 Groups of Special-Equivalent Strings Easy C# ✔️
894 All Possible Full Binary Trees Medium ➖
895 Maximum Frequency Stack Hard C# ✔️
896 Monotonic Array Easy C#, Java ✔️
897 Increasing Order Search Tree Easy C#, Java ✔️
898 Bitwise ORs of Subarrays Medium ➖
899 Orderly Queue Hard ➖
900 RLE Iterator Medium C# ✔️
901 Online Stock Span Medium C# ✔️
902 Numbers At Most N Given Digit Set Hard ➖
903 Valid Permutations for DI Sequence Hard ➖
904 Fruit Into Baskets Medium C#, Java ✔️
905 Sort Array By Parity Easy C# ✔️
906 Super Palindromes Hard C# ✔️
907 Sum of Subarray Minimums Medium ➖
908 Smallest Range I Easy C# ✔️
909 Snakes and Ladders Medium C# ✔️
910 Smallest Range II Medium ➖
911 Online Election Medium C# ✔️
912 Sort an Array Medium C# ✔️
913 Cat and Mouse Hard ➖
914 X of a Kind in a Deck of Cards Easy C#, Java ✔️
915 Partition Array into Disjoint Intervals Medium C# ✔️
916 Word Subsets Medium C#, Java ✔️
917 Reverse Only Letters Easy C# ✔️
918 Maximum Sum Circular Subarray Medium C# ✔️
919 Complete Binary Tree Inserter Medium C# ✔️
920 Number of Music Playlists Hard ➖
921 Minimum Add to Make Parentheses Valid Medium C# ✔️
922 Sort Array By Parity II Easy C# ✔️
923 3Sum With Multiplicity Medium C# ✔️
924 Minimize Malware Spread Hard ➖
925 Long Pressed Name Easy C# ✔️
926 Flip String to Monotone Increasing Medium C#, Java ✔️
927 Three Equal Parts Hard C# ✔️
928 Minimize Malware Spread II Hard ➖
929 Unique Email Addresses Easy C# ✔️
930 Binary Subarrays With Sum Medium C# ✔️
931 Minimum Falling Path Sum Medium C# ✔️
932 Beautiful Array Medium C# ✔️
933 Number of Recent Calls Easy C#, Java ✔️
934 Shortest Bridge Medium C# ✔️
935 Knight Dialer Medium C#, Java ✔️
936 Stamping The Sequence Hard C# ✔️
937 Reorder Data in Log Files Easy C# ✔️
938 Range Sum of BST Easy C#, Java ✔️
939 Minimum Area Rectangle Medium ➖
940 Distinct Subsequences II Hard ➖
941 Valid Mountain Array Easy C# ✔️
942 DI String Match Easy C# ✔️
943 Find the Shortest Superstring Hard ➖
944 Delete Columns to Make Sorted Easy C# ✔️
945 Minimum Increment to Make Array Unique Medium C# ✔️
946 Validate Stack Sequences Medium C#, Java ✔️
947 Most Stones Removed with Same Row or Column Medium C# ✔️
948 Bag of Tokens Medium C# ✔️
949 Largest Time for Given Digits Medium C# ✔️
950 Reveal Cards In Increasing Order Medium C# ✔️
951 Flip Equivalent Binary Trees Medium C# ✔️
952 Largest Component Size by Common Factor Hard ➖
953 Verifying an Alien Dictionary Easy C#, Java ✔️
954 Array of Doubled Pairs Medium C#, Java ✔️
955 Delete Columns to Make Sorted II Medium ➖
956 Tallest Billboard Hard ➖
957 Prison Cells After N Days Medium C# ✔️
958 Check Completeness of a Binary Tree Medium C# ✔️
959 Regions Cut By Slashes Medium ➖
960 Delete Columns to Make Sorted III Hard ➖
961 N-Repeated Element in Size 2N Array Easy C# ✔️
962 Maximum Width Ramp Medium C# ✔️
963 Minimum Area Rectangle II Medium ➖
964 Least Operators to Express Number Hard ➖
965 Univalued Binary Tree Easy C#, Java ✔️
966 Vowel Spellchecker Medium C#, Java ✔️
967 Numbers With Same Consecutive Differences Medium C# ✔️
968 Binary Tree Cameras Hard C# ✔️
969 Pancake Sorting Medium C# ✔️
970 Powerful Integers Medium C#, Java ✔️
971 Flip Binary Tree To Match Preorder Traversal Medium C# ✔️
972 Equal Rational Numbers Hard ➖
973 K Closest Points to Origin Medium C#, Java ✔️
974 Subarray Sums Divisible by K Medium C#, Java ✔️
975 Odd Even Jump Hard ➖
976 Largest Perimeter Triangle Easy C# ✔️
977 Squares of a Sorted Array Easy C# ✔️
978 Longest Turbulent Subarray Medium C# ✔️
979 Distribute Coins in Binary Tree Medium C#, Java ✔️
980 Unique Paths III Hard C# ✔️
981 Time Based Key-Value Store Medium C#, Java ✔️
982 Triples with Bitwise AND Equal To Zero Hard ➖
983 Minimum Cost For Tickets Medium C#, Java ✔️
984 String Without AAA or BBB Medium C# ✔️
985 Sum of Even Numbers After Queries Easy C# ✔️
986 Interval List Intersections Medium C# ✔️
987 Vertical Order Traversal of a Binary Tree Hard C# ✔️
988 Smallest String Starting From Leaf Medium C#, Java ✔️
989 Add to Array-Form of Integer Easy C#, Java ✔️
990 Satisfiability of Equality Equations Medium ➖
991 Broken Calculator Medium C#, Java ✔️
992 Subarrays with K Different Integers Hard ➖
993 Cousins in Binary Tree Easy C#, Java, Python ✔️
994 Rotting Oranges Medium C#, Java, JS ✔️
995 Minimum Number of K Consecutive Bit Flips Hard ➖
996 Number of Squareful Arrays Hard ➖
997 Find the Town Judge Easy C# ✔️
998 Maximum Binary Tree II Medium ➖
999 Available Captures for Rook Easy C#, Java ✔️
1000 Minimum Cost to Merge Stones Hard ➖
1001 Grid Illumination Hard ➖
1002 Find Common Characters Easy C# ✔️
1003 Check If Word Is Valid After Substitutions Medium C# ✔️
1004 Max Consecutive Ones III Medium C#, Java ✔️
1005 Maximize Sum Of Array After K Negations Easy C# ✔️
1006 Clumsy Factorial Medium C#, Java ✔️
1007 Minimum Domino Rotations For Equal Row Medium C# ✔️
1008 Construct Binary Search Tree from Preorder Traversal Medium C#, Java ✔️
1009 Complement of Base 10 Integer Easy C# ✔️
1010 Pairs of Songs With Total Durations Divisible by 60 Medium C# ✔️
1011 Capacity To Ship Packages Within D Days Medium C#, Java ✔️
1012 Numbers With Repeated Digits Hard ➖
1013 Partition Array Into Three Parts With Equal Sum Easy C# ✔️
1014 Best Sightseeing Pair Medium C# ✔️
1015 Smallest Integer Divisible by K Medium C# ✔️
1016 Binary String With Substrings Representing 1 To N Medium C# ✔️
1017 Convert to Base -2 Medium C# ✔️
1018 Binary Prefix Divisible By 5 Easy C# ✔️
1019 Next Greater Node In Linked List Medium C# ✔️
1020 Number of Enclaves Medium C# ✔️
1021 Remove Outermost Parentheses Easy C# ✔️
1022 Sum of Root To Leaf Binary Numbers Easy C# ✔️
1023 Camelcase Matching Medium C# ✔️
1024 Video Stitching Medium 〽️
1025 Divisor Game Easy C# ✔️
1026 Maximum Difference Between Node and Ancestor Medium C# ✔️
1027 Longest Arithmetic Subsequence Medium C# ✔️
1028 Recover a Tree From Preorder Traversal Hard C# ✔️
1029 Two City Scheduling Medium C# ✔️
1030 Matrix Cells in Distance Order Easy C#, Java ✔️
1031 Maximum Sum of Two Non-Overlapping Subarrays Medium C# ✔️
1032 Stream of Characters Hard ➖
1033 Moving Stones Until Consecutive Easy C# ✔️
1034 Coloring A Border Medium C# ✔️
1035 Uncrossed Lines Medium C# ✔️
1036 Escape a Large Maze Hard ➖
1037 Valid Boomerang Easy C# ✔️
1038 Binary Search Tree to Greater Sum Tree Medium C#, Java ✔️
1039 Minimum Score Triangulation of Polygon Medium ➖
1040 Moving Stones Until Consecutive II Medium ➖
1041 Robot Bounded In Circle Medium C#, Java ✔️
1042 Flower Planting With No Adjacent Medium C# ✔️
1043 Partition Array for Maximum Sum Medium C# ✔️
1044 Longest Duplicate Substring Hard 〽️
1045 Customers Who Bought All Products Medium MySQL, SQLServer ✔️
1046 Last Stone Weight Easy C#, Java ✔️
1047 Remove All Adjacent Duplicates In String Easy C#, Java ✔️
1048 Longest String Chain Medium C#, Java ✔️
1049 Last Stone Weight II Medium C# ✔️
1050 Actors and Directors Who Cooperated At Least Three Times Easy MySQL, SQLServer ✔️
1051 Height Checker Easy C# ✔️
1052 Grumpy Bookstore Owner Medium C# ✔️
1053 Previous Permutation With One Swap Medium C# ✔️
1054 Distant Barcodes Medium C# ✔️
1055 Shortest Way to Form String Medium ➖
1056 Confusing Number Easy C# ✔️
1057 Campus Bikes Medium ➖
1058 Minimize Rounding Error to Meet Target Medium ➖
1059 All Paths from Source Lead to Destination Medium C#, Java ✔️
1060 Missing Element in Sorted Array Medium C# ✔️
1061 Lexicographically Smallest Equivalent String Medium ➖
1062 Longest Repeating Substring Medium C# ✔️
1063 Number of Valid Subarrays Hard ➖
1064 Fixed Point Easy C# ✔️
1065 Index Pairs of a String Easy C# ✔️
1066 Campus Bikes II Medium ➖
1067 Digit Count in Range Hard ➖
1068 Product Sales Analysis I Easy MySQL, SQLServer ✔️
1069 Product Sales Analysis II Easy MySQL, SQLServer ✔️
1070 Product Sales Analysis III Medium MySQL, SQLServer ✔️
1071 Greatest Common Divisor of Strings Easy C# ✔️
1072 Flip Columns For Maximum Number of Equal Rows Medium C# ✔️
1073 Adding Two Negabinary Numbers Medium C# ✔️
1074 Number of Submatrices That Sum to Target Hard C# ✔️
1075 Project Employees I Easy MySQL, SQLServer ✔️
1076 Project Employees II Easy MySQL, SQLServer ✔️
1077 Project Employees III Medium MySQL, SQLServer ✔️
1078 Occurrences After Bigram Easy C# ✔️
1079 Letter Tile Possibilities Medium C# ✔️
1080 Insufficient Nodes in Root to Leaf Paths Medium ➖
1081 Smallest Subsequence of Distinct Characters Medium C# ✔️
1082 Sales Analysis I Easy MySQL, SQLServer ✔️
1083 Sales Analysis II Easy MySQL, SQLServer ✔️
1084 Sales Analysis III Easy MySQL, SQLServer ✔️
1085 Sum of Digits in the Minimum Number Easy C# ✔️
1086 High Five Easy C# ✔️
1087 Brace Expansion Medium C# ✔️
1088 Confusing Number II Hard ➖
1089 Duplicate Zeros Easy C# ✔️
1090 Largest Values From Labels Medium C# ✔️
1091 Shortest Path in Binary Matrix Medium C#, Java ✔️
1092 Shortest Common Supersequence Hard ➖
1093 Statistics from a Large Sample Medium C# ✔️
1094 Car Pooling Medium C# ✔️
1095 Find in Mountain Array Hard ➖
1096 Brace Expansion II Hard ➖
1097 Game Play Analysis V Hard MySQL, SQLServer ✔️
1098 Unpopular Books Medium MySQL, SQLServer ✔️
1099 Two Sum Less Than K Easy C# ✔️
1100 Find K-Length Substrings With No Repeated Characters Medium C# ✔️
1101 The Earliest Moment When Everyone Become Friends Medium C# ✔️
1102 Path With Maximum Minimum Value Medium ➖
1103 Distribute Candies to People Easy C#, Java ✔️
1104 Path In Zigzag Labelled Binary Tree Medium C# ✔️
1105 Filling Bookcase Shelves Medium C# ✔️
1106 Parsing A Boolean Expression Hard ➖
1107 New Users Daily Count Medium MySQL, SQLServer ✔️
1108 Defanging an IP Address Easy C# ✔️
1109 Corporate Flight Bookings Medium C# ✔️
1110 Delete Nodes And Return Forest Medium C# ✔️
1111 Maximum Nesting Depth of Two Valid Parentheses Strings Medium C# ✔️
1112 Highest Grade For Each Student Medium MySQL, SQLServer ✔️
1113 Reported Posts Easy MySQL, SQLServer ✔️
1114 Print in Order Easy C# ✔️
1115 Print FooBar Alternately Medium ➖
1116 Print Zero Even Odd Medium ➖
1117 Building H2O Medium ➖
1118 Number of Days in a Month Easy C# ✔️
1119 Remove Vowels from a String Easy C# ✔️
1120 Maximum Average Subtree Medium C# ✔️
1121 Divide Array Into Increasing Sequences Hard ➖
1122 Relative Sort Array Easy C#, Java ✔️
1123 Lowest Common Ancestor of Deepest Leaves Medium C# ✔️
1124 Longest Well-Performing Interval Medium C# ✔️
1125 Smallest Sufficient Team Hard ➖
1126 Active Businesses Medium SQLServer ✔️
1127 User Purchase Platform Hard MySQL, SQLServer ✔️
1128 Number of Equivalent Domino Pairs Easy C# ✔️
1129 Shortest Path with Alternating Colors Medium ➖
1130 Minimum Cost Tree From Leaf Values Medium ➖
1131 Maximum of Absolute Value Expression Medium C#, Java ✔️
1132 Reported Posts II Medium MySQL, SQLServer ✔️
1133 Largest Unique Number Easy C#, Java ✔️
1134 Armstrong Number Easy C#, Java ✔️
1135 Connecting Cities With Minimum Cost Medium C#, Java ✔️
1136 Parallel Courses Medium C# ✔️
1137 N-th Tribonacci Number Easy C#, Java, Python ✔️
1138 Alphabet Board Path Medium C# ✔️
1139 Largest 1-Bordered Square Medium ➖
1140 Stone Game II Medium ➖
1141 User Activity for the Past 30 Days I Easy MySQL, SQLServer ✔️
1142 User Activity for the Past 30 Days II Easy MySQL, SQLServer ✔️
1143 Longest Common Subsequence Medium C#, Java, Python ✔️
1144 Decrease Elements To Make Array Zigzag Medium C# ✔️
1145 Binary Tree Coloring Game Medium ➖
1146 Snapshot Array Medium C# ✔️
1147 Longest Chunked Palindrome Decomposition Hard ➖
1148 Article Views I Easy MySQL, SQLServer ✔️
1149 Article Views II Medium MySQL, SQLServer ✔️
1150 Check If a Number Is Majority Element in a Sorted Array Easy C# ✔️
1151 Minimum Swaps to Group All 1's Together Medium C# ✔️
1152 Analyze User Website Visit Pattern Medium C# ✔️
1153 String Transforms Into Another String Hard ➖
1154 Day of the Year Easy C# ✔️
1155 Number of Dice Rolls With Target Sum Medium ➖
1156 Swap For Longest Repeated Character Substring Medium C# ✔️
1157 Online Majority Element In Subarray Hard ➖
1158 Market Analysis I Medium SQLServer ✔️
1159 Market Analysis II Hard MySQL, SQLServer ✔️
1160 Find Words That Can Be Formed by Characters Easy C# ✔️
1161 Maximum Level Sum of a Binary Tree Medium C#, Java ✔️
1162 As Far from Land as Possible Medium C#, Java ✔️
1163 Last Substring in Lexicographical Order Hard ➖
1164 Product Price at a Given Date Medium MySQL ✔️
1165 Single-Row Keyboard Easy C#, Java ✔️
1166 Design File System Medium C# ✔️
1167 Minimum Cost to Connect Sticks Medium C#, Java ✔️
1168 Optimize Water Distribution in a Village Hard C# ✔️
1169 Invalid Transactions Medium C# ✔️
1170 Compare Strings by Frequency of the Smallest Character Medium C# ✔️
1171 Remove Zero Sum Consecutive Nodes from Linked List Medium C# ✔️
1172 Dinner Plate Stacks Hard ➖
1173 Immediate Food Delivery I Easy MySQL, SQLServer ✔️
1174 Immediate Food Delivery II Medium MySQL, SQLServer ✔️
1175 Prime Arrangements Easy C# ✔️
1176 Diet Plan Performance Easy C# ✔️
1177 Can Make Palindrome from Substring Medium C# ✔️
1178 Number of Valid Words for Each Puzzle Hard ➖
1179 Reformat Department Table Easy MySQL, SQLServer ✔️
1180 Count Substrings with Only One Distinct Letter Easy C# ✔️
1181 Before and After Puzzle Medium C# ✔️
1182 Shortest Distance to Target Color Medium C#, Java ✔️
1183 Maximum Number of Ones Hard ➖
1184 Distance Between Bus Stops Easy C# ✔️
1185 Day of the Week Easy C# ✔️
1186 Maximum Subarray Sum with One Deletion Medium ➖
1187 Make Array Strictly Increasing Hard ➖
1188 Design Bounded Blocking Queue Medium ➖
1189 Maximum Number of Balloons Easy C# ✔️
1090 Reverse Substrings Between Each Pair of Parentheses Medium C#, Java ✔️
1191 K-Concatenation Maximum Sum Medium C# ✔️
1192 Critical Connections in a Network Hard C# ✔️
1193 Monthly Transactions I Medium MySQL, SQLServer ✔️
1194 Tournament Winners Hard MySQL, SQLServer ✔️
1195 Fizz Buzz Multithreaded Medium ➖
1196 How Many Apples Can You Put into the Basket Easy C# ✔️
1197 Minimum Knight Moves Medium C#, Java ✔️
1198 Find Smallest Common Element in All Rows Medium C#, Java ✔️
1199 Minimum Time to Build Blocks Hard ➖
1200 Minimum Absolute Difference Easy C# ✔️
1201 Ugly Number III Medium C# ✔️
1202 Smallest String With Swaps Medium ➖
1203 Sort Items by Groups Respecting Dependencies Hard ➖
1204 Last Person to Fit in the Bus Medium MySQL, SQLServer ✔️
1205 Monthly Transactions II Medium MySQL, SQLServer ✔️
1206 Design Skiplist Hard ➖
1207 Unique Number of Occurrences Easy C# ✔️
1208 Get Equal Substrings Within Budget Medium C# ✔️
1209 Remove All Adjacent Duplicates in String II Medium C#, Java ✔️
1210 Minimum Moves to Reach Target with Rotations Hard ➖
1211 Queries Quality and Percentage Easy MySQL, SQLServer ✔️
1212 Team Scores in Football Tournament Medium SQLServer ✔️
1213 Intersection of Three Sorted Arrays Easy C# ✔️
1214 Two Sum BSTs Medium C# ✔️
1215 Stepping Numbers Medium C# ✔️
1216 Valid Palindrome III Hard ➖
1217 Minimum Cost to Move Chips to The Same Position Easy C# ✔️
1218 Longest Arithmetic Subsequence of Given Difference Medium C# ✔️
1219 Path with Maximum Gold Medium C# ✔️
1220 Count Vowels Permutation Hard ➖
1221 Split a String in Balanced Strings Easy C# ✔️
1222 Queens That Can Attack the King Medium C# ✔️
1223 Dice Roll Simulation Hard ➖
1224 Maximum Equal Frequency Hard ➖
1225 Report Contiguous Dates Hard MySQL, SQLServer ✔️
1226 The Dining Philosophers Medium ➖
1227 Airplane Seat Assignment Probability Medium C#, Java ✔️
1228 Missing Number In Arithmetic Progression Easy C#, Java ✔️
1229 Meeting Scheduler Medium C#, Java ✔️
1230 Toss Strange Coins Medium ➖
1231 Divide Chocolate Hard ➖
1232 Check If It Is a Straight Line Easy C# ✔️
1233 Remove Sub-Folders from the Filesystem Medium C# ✔️
1234 Replace the Substring for Balanced String Medium C# ✔️
1235 Maximum Profit in Job Scheduling Hard ➖
1236 Web Crawler Medium C# ✔️
1237 Find Positive Integer Solution for a Given Equation Medium C# ✔️
1238 Circular Permutation in Binary Representation Medium ➖
1239 Maximum Length of a Concatenated String with Unique Characters Medium C#, Java ✔️
1240 Tiling a Rectangle with the Fewest Squares Hard ➖
1241 Number of Comments per Post Easy MySQL, SQLServer ✔️
1242 Web Crawler Multithreaded Medium ➖
1243 Array Transformation Easy C# ✔️
1244 Design A Leaderboard Medium C# ✔️
1245 Tree Diameter Medium C# ✔️
1246 Palindrome Removal Hard ➖
1247 Minimum Swaps to Make Strings Equal Medium C# ✔️
1248 Count Number of Nice Subarrays Medium C# ✔️
1249 Minimum Remove to Make Valid Parentheses Medium C#, Java ✔️
1250 Check If It Is a Good Array Hard ➖
1251 Average Selling Price Easy MySQL, SQLServer ✔️
1252 Cells with Odd Values in a Matrix Easy C# ✔️
1253 Reconstruct a 2-Row Binary Matrix Medium C# ✔️
1254 Number of Closed Islands Medium C# ✔️
1255 Maximum Score Words Formed by Letters Hard ➖
1256 Encode Number Medium C# ✔️
1257 Smallest Common Region Medium C# ✔️
1258 Synonymous Sentences Medium ➖
1259 Handshakes That Don't Cross Hard ➖
1260 Shift 2D Grid Easy C# ✔️
1261 Find Elements in a Contaminated Binary Tree Medium C#, Java ✔️
1262 Greatest Sum Divisible by Three Medium C# ✔️
1263 Minimum Moves to Move a Box to Their Target Location Hard ➖
1264 Page Recommendations Medium MySQL, SQLServer ✔️
1265 Print Immutable Linked List in Reverse Medium C# ✔️
1266 Minimum Time Visiting All Points Easy C# ✔️
1267 Count Servers that Communicate Medium C# ✔️
1268 Search Suggestions System Medium C#, Java ✔️
1269 Number of Ways to Stay in the Same Place After Some Steps Hard ➖
1270 All People Report to the Given Manager Medium MySQL, SQLServer ✔️
1271 Hexspeak Easy C# ✔️
1272 Remove Interval Medium C# ✔️
1273 Delete Tree Nodes Medium ➖
1274 Number of Ships in a Rectangle Hard ➖
1275 Find Winner on a Tic Tac Toe Game Easy C#, Java ✔️
1276 Number of Burgers with No Waste of Ingredients Medium C# ✔️
1277 Count Square Submatrices with All Ones Medium C# ✔️
1278 Palindrome Partitioning III Hard C# ✔️
1279 Traffic Light Controlled Intersection Easy C# ✔️
1280 Students and Examinations Easy MySQL, SQLServer ✔️
1281 Subtract the Product and Sum of Digits of an Integer Easy C# ✔️
1282 Group the People Given the Group Size They Belong To Medium C#, Java ✔️
1283 Find the Smallest Divisor Given a Threshold Medium C# ✔️
1284 Minimum Number of Flips to Convert Binary Matrix to Zero Matrix Hard ➖
1285 Find the Start and End Number of Continuous Ranges Medium MySQL, SQLServer ✔️
1286 Iterator for Combination Medium C# ✔️
1287 Element Appearing More Than 25% In Sorted Array Easy C# ✔️
1288 Remove Covered Intervals Medium C# ✔️
1289 Minimum Falling Path Sum II Hard ➖
1290 Convert Binary Number in a Linked List to Integer Easy C# ✔️
1291 Sequential Digits Medium C# ✔️
1292 Maximum Side Length of a Square with Sum Less than or Equal to Threshold Medium C# ✔️
1293 Shortest Path in a Grid with Obstacles Elimination Hard ➖
1294 Weather Type in Each Country Easy MySQL, SQLServer ✔️
1295 Find Numbers with Even Number of Digits Easy C# ✔️
1296 Divide Array in Sets of K Consecutive Numbers Medium C#, Java ✔️
1297 Maximum Number of Occurrences of a Substring Medium C# ✔️
1298 Maximum Candies You Can Get from Boxes Hard ➖
1299 Replace Elements with Greatest Element on Right Side Easy C# ✔️
1300 Sum of Mutated Array Closest to Target Medium C# ✔️
1301 Number of Paths with Max Score Hard ➖
1302 Deepest Leaves Sum Medium C#, Java ✔️
1303 Find the Team Size Easy MySQL, SQLServer ✔️
1304 Find N Unique Integers Sum up to Zero Easy C#, Java ✔️
1305 All Elements in Two Binary Search Trees Medium C#, Java ✔️
1306 Jump Game III Medium C#, Java ✔️
1307 Verbal Arithmetic Puzzle Hard ➖
1308 Running Total for Different Genders Medium MySQL, SQLServer ✔️
1309 Decrypt String from Alphabet to Integer Mapping Easy C# ✔️
1310 XOR Queries of a Subarray Medium C#, Java ✔️
1311 Get Watched Videos by Your Friends Medium C# ✔️
1312 Minimum Insertion Steps to Make a String Palindrome Hard ➖
1313 Decompress Run-Length Encoded List Easy C#, Java ✔️
1314 Matrix Block Sum Medium C# ✔️
1315 Sum of Nodes with Even-Valued Grandparent Medium C#, Java ✔️
1316 Distinct Echo Substrings Hard ➖
1317 Convert Integer to the Sum of Two No-Zero Integers Easy C# ✔️
1318 Minimum Flips to Make a OR b Equal to c Medium C# ✔️
1319 Number of Operations to Make Network Connected Medium C# ✔️
1320 Minimum Distance to Type a Word Using Two Fingers Hard ➖
1321 Restaurant Growth Medium MySQL, SQLServer ✔️
1322 Ads Performance Easy MySQL, SQLServer ✔️
1323 Maximum 69 Number Easy C#, Java ✔️
1324 Print Words Vertically Medium C# ✔️
1325 Delete Leaves With a Given Value Medium C#, Java ✔️
1326 Minimum Number of Taps to Open to Water a Garden Hard ➖
1327 List the Products Ordered in a Period Easy MySQL, SQLServer ✔️
1328 Break a Palindrome Medium C#, Java ✔️
1329 Sort the Matrix Diagonally Medium C#, Java ✔️
1330 Reverse Subarray To Maximize Array Value Hard ➖
1331 Rank Transform of an Array Easy C# ✔️
1332 Remove Palindromic Subsequences Easy C#, Java ✔️
1333 Filter Restaurants by Vegan-Friendly, Price and Distance Medium C# ✔️
1334 Find the City With the Smallest Number of Neighbors at a Threshold Distance Medium ➖
1335 Minimum Difficulty of a Job Schedule Hard ➖
1336 Number of Transactions per Visit Hard MySQL, SQLServer ✔️
1337 The K Weakest Rows in a Matrix Easy C#, Java ✔️
1338 Reduce Array Size to The Half Medium C# ✔️
1339 Maximum Product of Splitted Binary Tree Medium C# ✔️
1340 Jump Game V Hard ➖
1341 Movie Rating Medium MySQL, SQLServer ✔️
1342 Number of Steps to Reduce a Number to Zero Easy C#, Java ✔️
1343 Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold Medium C#, Java ✔️
1344 Angle Between Hands of a Clock Medium C# ✔️
1345 Jump Game IV Hard C# ✔️
1346 Check If N and Its Double Exist Easy C# ✔️
1347 Minimum Number of Steps to Make Two Strings Anagram Medium C# ✔️
1348 Tweet Counts Per Frequency Medium C# ✔️
1349 Maximum Students Taking Exam Hard ➖
1350 Students With Invalid Departments Easy MySQL, SQLServer ✔️
1351 Count Negative Numbers in a Sorted Matrix Easy C# ✔️
1352 Product of the Last K Numbers Medium C# ✔️
1353 Maximum Number of Events That Can Be Attended Medium C# ✔️
1354 Construct Target Array With Multiple Sums Hard C#, Java ✔️
1355 Activity Participants Medium MySQL, SQLServer ✔️
1356 Sort Integers by The Number of 1 Bits Easy C# ✔️
1357 Apply Discount Every n Orders Medium C# ✔️
1358 Number of Substrings Containing All Three Characters Medium C# ✔️
1359 Count All Valid Pickup and Delivery Options Hard ➖
1360 Number of Days Between Two Dates Easy C# ✔️
1361 Validate Binary Tree Node Medium C# ✔️
1362 Closest Divisors Medium C#, Java ✔️
1363 Largest Multiple of Three Hard ➖
1364 Number of Trusted Contacts of a Customer Medium MySQL, SQLServer ✔️
1365 How Many Numbers Are Smaller Than the Current Number Easy C#, Java ✔️
1366 Rank Teams by Votes Medium C# ✔️
1367 Linked List in Binary Tree Medium C#, Java ✔️
1368 Minimum Cost to Make at Least One Valid Path in a Grid Hard ➖
1369 Get the Second Most Recent Activity Hard MySQL, SQLServer ✔️
1370 Increasing Decreasing String Easy C# ✔️
1371 Find the Longest Substring Containing Vowels in Even Counts Medium C# ✔️
1372 Longest ZigZag Path in a Binary Tree Medium C# ✔️
1373 Maximum Sum BST in Binary Tree Hard ➖
1374 Generate a String With Characters That Have Odd Counts Easy C#, Java ✔️
1375 Bulb Switcher III Medium C# ✔️
1376 Time Needed to Inform All Employees Medium C# ✔️
1377 Frog Position After T Seconds Hard ➖
1378 Replace Employee ID With The Unique Identifier Easy MySQL, SQLServer ✔️
1379 Find a Corresponding Node of a Binary Tree in a Clone of That Tree Medium C#, Java ✔️
1380 Lucky Numbers in a Matrix Easy C# ✔️
1381 Design a Stack With Increment Operation Medium C# ✔️
1382 Balance a Binary Search Tree Medium C# ✔️
1383 Maximum Performance of a Team Hard Java ✔️
1384 Total Sales Amount by Year Hard MySQL ✔️
1385 Find the Distance Value Between Two Arrays Easy C# ✔️
1386 Cinema Seat Allocation Medium C# ✔️
1387 Sort Integers by The Power Value Medium C# ✔️
1388 Pizza With 3n Slices Hard ➖
1389 Create Target Array in the Given Order Easy C#, Java ✔️
1390 Four Divisors Medium C# ✔️
1391 Check if There is a Valid Path in a Grid Medium C# ✔️
1392 Longest Happy Prefix Hard ➖
1393 Capital Gain/Loss Medium MySQL, SQLServer ✔️
1394 Find Lucky Integer in an Array Easy C# ✔️
1395 Count Number of Teams Medium C#, Java ✔️
1396 Design Underground System Medium C# ✔️
1397 Find All Good Strings Hard ➖
1398 Customers Who Bought Products A and B but Not C Medium MySQL, SQLServer ✔️
1399 Count Largest Group Easy C# ✔️
1400 Construct K Palindrome Strings Medium C# ✔️
1401 Circle and Rectangle Overlapping Medium C# ✔️
1402 Reducing Dishes Hard C# ✔️
1403 Minimum Subsequence in Non-Increasing Order Easy C# ✔️
1404 Number of Steps to Reduce a Number in Binary Representation to One Medium C# ✔️
1405 Longest Happy String Medium ➖
1406 Stone Game III Hard ➖
1407 Top Travellers Easy MySQL, SQLServer ✔️
1408 String Matching in an Array Easy C# ✔️
1409 Queries on a Permutation With Key Medium C# ✔️
1410 HTML Entity Parser Medium C#, Java ✔️
1411 Number of Ways to Paint N × 3 Grid Hard ➖
1412 Find the Quiet Students in All Exams Hard MySQL, SQLServer ✔️
1413 Minimum Value to Get Positive Step by Step Sum Easy C# ✔️
1414 Find the Minimum Number of Fibonacci Numbers Whose Sum Is K Medium C# ✔️
1415 The k-th Lexicographical String of All Happy Strings of Length n Medium C# ✔️
1416 Restore The Array Hard ➖
1417 Reformat The String Easy C# ✔️
1418 Display Table of Food Orders in a Restaurant Medium C# ✔️
1419 Minimum Number of Frogs Croaking Medium C# ✔️
1420 Build Array Where You Can Find The Maximum Exactly K Comparisons Hard ➖
1421 NPV Queries Medium MySQL, SQLServer ✔️
1422 Maximum Score After Splitting a String Easy C# ✔️
1423 Maximum Points You Can Obtain from Cards Medium C#, Java ✔️
1424 Diagonal Traverse II Medium C# ✔️
1425 Constrained Subsequence Sum Hard ➖
1426 Counting Elements Easy C# ✔️
1427 Perform String Shifts Easy C# ✔️
1428 Leftmost Column with at Least a One Medium C# ✔️
1429 First Unique Number Medium C# ✔️
1430 Check If a String Is a Valid Sequence from Root to Leaves Path in a Binary Tree Medium C# ✔️
1431 Kids With the Greatest Number of Candies Easy C#, Java ✔️
1432 Max Difference You Can Get From Changing an Integer Medium C# ✔️
1433 Check If a String Can Break Another String Medium C# ✔️
1434 Number of Ways to Wear Different Hats to Each Other Hard ➖
1435 Create a Session Bar Chart Easy MySQL, SQLServer ✔️
1436 Destination City Easy C# ✔️
1437 Check If All 1's Are at Least Length K Places Away Easy C#, Java ✔️
1438 Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit Medium C# ✔️
1439 Find the Kth Smallest Sum of a Matrix With Sorted Rows Hard ➖
1440 Evaluate Boolean Expression Medium MySQL, SQLServer ✔️
1441 Build an Array With Stack Operations Easy C# ✔️
1442 Count Triplets That Can Form Two Arrays of Equal XOR Medium C# ✔️
1443 Minimum Time to Collect All Apples in a Tree Medium ➖
1444 Number of Ways of Cutting a Pizza Hard ➖
1445 Apples & Oranges Medium MySQL, SQLServer ✔️
1446 Consecutive Characters Easy C# ✔️
1447 Simplified Fractions Medium C# ✔️
1448 Count Good Nodes in Binary Tree Medium C#, Java, Python ✔️
1449 Form Largest Integer With Digits That Add up to Target Hard ➖
1450 Number of Students Doing Homework at a Given Time Easy C# ✔️
1451 Rearrange Words in a Sentence Medium C# ✔️
1452 People Whose List of Favorite Companies Is Not a Subset of Another List Medium C# ✔️
1453 Maximum Number of Darts Inside of a Circular Dartboard Hard ➖
1454 Active Users Medium MySQL, SQLServer ✔️
1455 Check If a Word Occurs As a Prefix of Any Word in a Sentence Easy C# ✔️
1456 Maximum Number of Vowels in a Substring of Given Length Medium C# ✔️
1457 Pseudo-Palindromic Paths in a Binary Tree Medium C#, Java ✔️
1458 Max Dot Product of Two Subsequences Hard ➖
1459 Rectangles Area Medium MySQL, SQLServer ✔️
1460 Make Two Arrays Equal by Reversing Sub-arrays Easy C# ✔️
1461 Check If a String Contains All Binary Codes of Size K Medium C#, Java ✔️
1462 Course Schedule IV Medium C# ✔️
1463 Cherry Pickup II Hard ➖
1464 Maximum Product of Two Elements in an Array Easy C# ✔️
1465 Maximum Area of a Piece of Cake After Horizontal and Vertical Cuts Medium C#, Java ✔️
1466 Reorder Routes to Make All Paths Lead to the City Zero Medium C# ✔️
1467 Probability of a Two Boxes Having The Same Number of Distinct Balls Hard ➖
1468 Calculate Salaries Medium MySQL, SQLServer ✔️
1469 Find All The Lonely Nodes Easy C#, Java ✔️
1470 Shuffle the Array Easy C#, Java ✔️
1471 The k Strongest Values in an Array Medium C# ✔️
1472 Design Browser History Medium C# ✔️
1473 Paint House III Hard ➖
1474 Delete N Nodes After M Nodes of a Linked List Easy C# ✔️
1475 Final Prices With a Special Discount in a Shop Easy C# ✔️
1476 Subrectangle Queries Medium C# ✔️
1477 Find Two Non-overlapping Sub-arrays Each With Target Sum Medium C# ✔️
1478 Allocate Mailboxes Hard ➖
1479 Sales by Day of the Week Hard SQLServer ✔️
1480 Running Sum of 1d Array Easy C#, Java ✔️
1481 Least Number of Unique Integers after K Removals Medium C# ✔️
1482 Minimum Number of Days to Make m Bouquets Medium C# ✔️
1483 Kth Ancestor of a Tree Node Hard ➖
1484 Group Sold Products By The Date Easy MySQL, SQLServer ✔️
1485 Clone Binary Tree With Random Pointer Medium C# ✔️
1486 XOR Operation in an Array Easy C#, Java ✔️
1487 Making File Names Unique Medium ➖
1488 Avoid Flood in The City Medium C#, Java ✔️
1489 Find Critical and Pseudo-Critical Edges in Minimum Spanning Tree Hard ➖
1490 Clone N-ary Tree Medium C#, Java ✔️
1491 Average Salary Excluding the Minimum and Maximum Salary Easy C# ✔️
1492 The kth Factor of n Medium C# ✔️
1493 Longest Subarray of 1's After Deleting One Element Medium C# ✔️
1494 Parallel Courses II Hard ➖
1495 Friendly Movies Streamed Last Month Easy MySQL, SQLServer ✔️
1496 Path Crossing Easy C#, Java ✔️
1497 Check If Array Pairs Are Divisible by k Medium C# ✔️
1498 Number of Subsequences That Satisfy the Given Sum Condition Medium C# ✔️
1499 Max Value of Equation Hard ➖
1500 Design a File Sharing System Medium C# ✔️
1501 Countries You Can Safely Invest In Medium SQLServer ✔️
1502 Can Make Arithmetic Progression From Sequence Easy C# ✔️
1503 Last Moment Before All Ants Fall Out of a Plank Medium C# ✔️
1504 Count Submatrices With All Ones Medium C# ✔️
1505 Minimum Possible Integer After at Most K Adjacent Swaps On Digits Hard ➖
1506 Find Root of N-Ary Tree Medium C# ✔️
1507 Reformat Date Easy C# ✔️
1508 Range Sum of Sorted Subarray Sums Medium C# ✔️
1509 Minimum Difference Between Largest and Smallest Value in Three Moves Medium C# ✔️
1510 Stone Game IV Hard ➖
1511 Customer Order Frequency Easy MySQL, SQLServer ✔️
1512 Number of Good Pairs Easy C#, Java ✔️
1513 Number of Substrings With Only 1s Medium C# ✔️
1514 Path with Maximum Probability Medium C# ✔️
1515 Best Position for a Service Centre Hard ➖
1516 Move Sub-Tree of N-Ary Tree Hard ➖
1517 Find Users With Valid E-Mails Easy MySQL, SQLServer ✔️
1518 Water Bottles Easy C# ✔️
1519 Number of Nodes in the Sub-Tree With the Same Label Medium C# ✔️
1520 Maximum Number of Non-Overlapping Substrings Hard ➖
1521 Find a Value of a Mysterious Function Closest to Target Hard ➖
1522 Diameter of N-Ary Tree Medium C# ✔️
1523 Count Odd Numbers in an Interval Range Easy C# ✔️
1524 Number of Sub-arrays With Odd Sum Medium C# ✔️
1525 Number of Good Ways to Split a String Medium C# ✔️
1526 Minimum Number of Increments on Subarrays to Form a Target Array Hard ➖
1527 Patients With a Condition Easy MySQL, SQLServer ✔️
1528 Shuffle String Easy C# ✔️
1529 Bulb Switcher IV Medium C# ✔️
1530 Number of Good Leaf Nodes Pairs Medium ➖
1531 String Compression II Hard ➖
1532 The Most Recent Three Orders Medium MySQL, SQLServer ✔️
1533 Find the Index of the Large Integer Medium C# ✔️
1534 Count Good Triplets Easy C# ✔️
1535 Find the Winner of an Array Game Medium C# ✔️
1536 Minimum Swaps to Arrange a Binary Grid Medium ➖
1537 Get the Maximum Score Hard ➖
1538 Guess the Majority in a Hidden Array Medium ➖
1539 Kth Missing Positive Number Easy C# ✔️
1540 Can Convert String in K Moves Medium C# ✔️
1541 Minimum Insertions to Balance a Parentheses String Medium C# ✔️
1542 Find Longest Awesome Substring Hard ➖
1543 Fix Product Name Format Easy MySQL, SQLServer ✔️
1544 Make The String Great Easy C# ✔️
1545 Find Kth Bit in Nth Binary String Medium C# ✔️
1546 Maximum Number of Non-Overlapping Subarrays With Sum Equals Target Medium ➖
1547 Minimum Cost to Cut a Stick Hard ➖
1548 The Most Similar Path in a Graph Hard ➖
1549 The Most Recent Orders for Each Product Medium MySQL, SQLServer ✔️
1550 Three Consecutive Odds Easy C# ✔️
1551 Minimum Operations to Make Array Equal Medium C#, Java ✔️
1552 Magnetic Force Between Two Balls Medium ➖
1553 Minimum Number of Days to Eat N Oranges Hard ➖
1554 Strings Differ by One Character Medium C# ✔️
1555 Bank Account Summary Medium MySQL, SQLServer ✔️
1556 Thousand Separator Easy C# ✔️
1557 Minimum Number of Vertices to Reach All Nodes Medium C# ✔️
1558 Minimum Numbers of Function Calls to Make Target Array Medium C# ✔️
1559 Detect Cycles in 2D Grid Medium C# ✔️
1560 Most Visited Sector in a Circular Track Easy C# ✔️
1561 Maximum Number of Coins You Can Get Medium C#, Java ✔️
1562 Find Latest Group of Size M Medium ➖
1563 Stone Game V Hard ➖
1564 Put Boxes Into the Warehouse I Medium C#, Java ✔️
1565 Unique Orders and Customers Per Month Easy MySQL, SQLServer ✔️
1566 Detect Pattern of Length M Repeated K or More Times Easy C# ✔️
1567 Maximum Length of Subarray With Positive Product Medium C# ✔️
1568 Minimum Number of Days to Disconnect Island Hard ➖
1569 Number of Ways to Reorder Array to Get Same BST Hard ➖
1570 Dot Product of Two Sparse Vectors Medium C# ✔️
1571 Warehouse Manager Easy MySQL, SQLServer ✔️
1572 Matrix Diagonal Sum Easy C# ✔️
1573 Number of Ways to Split a String Medium ➖
1574 Shortest Subarray to be Removed to Make Array Sorted Medium C# ✔️
1575 Count All Possible Routes Hard ➖
1576 Replace All ?'s to Avoid Consecutive Repeating Characters Easy C# ✔️
1577 Number of Ways Where Square of Number Is Equal to Product of Two Numbers Medium C# ✔️
1578 Minimum Deletion Cost to Avoid Repeating Letters Medium C# ✔️
1579 Remove Max Number of Edges to Keep Graph Fully Traversable Hard ➖
1580 Put Boxes Into the Warehouse II Medium ➖
1581 Customer Who Visited but Did Not Make Any Transactions Easy MySQL, SQLServer ✔️
1582 Special Positions in a Binary Matrix Easy C# ✔️
1583 Count Unhappy Friends Medium C# ✔️
1584 Min Cost to Connect All Points Medium C# ✔️
1585 Check If String Is Transformable With Substring Sort Operations Hard ➖
1586 Binary Search Tree Iterator II Medium C# ✔️
1587 Bank Account Summary II Easy MySQL, SQLServer ✔️
1588 Sum of All Odd Length Subarrays Easy C# ✔️
1589 Maximum Sum Obtained of Any Permutation Medium ➖
1590 Make Sum Divisible by P Medium C#, Java ✔️
1591 Strange Printer II Hard ➖
1592 Rearrange Spaces Between Words Easy C# ✔️
1593 Split a String Into the Max Number of Unique Substrings Medium C# ✔️
1594 Maximum Non Negative Product in a Matrix Medium C# ✔️
1595 Minimum Cost to Connect Two Groups of Points Hard ➖
1596 The Most Frequently Ordered Products for Each Customer Medium MySQL, SQLServer ✔️
1597 Build Binary Expression Tree From Infix Expression Hard ➖
1598 Crawler Log Folder Easy C# ✔️
1599 Maximum Profit of Operating a Centennial Wheel Medium C# ✔️
1600 Throne Inheritance Medium C# ✔️
1601 Maximum Number of Achievable Transfer Requests Hard ➖
1602 Find Nearest Right Node in Binary Tree Medium C#, Java ✔️
1603 Design Parking System Easy C# ✔️
1604 Alert Using Same Key-Card Three or More Times in a One Hour Period Medium ➖
1605 Find Valid Matrix Given Row and Column Sums Medium C# ✔️
1606 Find Servers That Handled Most Number of Requests Hard ➖
1607 Sellers With No Sales Easy MySQL, SQLServer ✔️
1608 Special Array With X Elements Greater Than or Equal X Easy C# ✔️
1609 Even Odd Tree Medium C# ✔️
1610 Maximum Number of Visible Points Hard ➖
1611 Minimum One Bit Operations to Make Integers Zero Hard ➖
1612 Check If Two Expression Trees are Equivalent Medium C# ✔️
1613 Find the Missing IDs Medium MySQL, SQLServer ✔️
1614 Maximum Nesting Depth of the Parentheses Easy C#, Java ✔️
1615 Maximal Network Rank Medium C# ✔️
1616 Split Two Strings to Make Palindrome Medium C# ✔️
1617 Count Subtrees With Max Distance Between Cities Hard ➖
1618 Maximum Font to Fit a Sentence in a Screen Medium C# ✔️
1619 Mean of Array After Removing Some Elements Easy C# ✔️
1620 Coordinate With Maximum Network Quality Medium C# ✔️
1621 Number of Sets of K Non-Overlapping Line Segments Medium ➖
1622 Fancy Sequence Hard ➖
1623 All Valid Triplets That Can Represent a Country Easy MySQL, SQLServer ✔️
1624 Largest Substring Between Two Equal Characters Easy C# ✔️
1625 Lexicographically Smallest String After Applying Operations Medium C# ✔️
1626 Best Team With No Conflicts Medium C# ✔️
1627 Graph Connectivity With Threshold Hard ➖
1628 Design an Expression Tree With Evaluate Function Medium ➖
1629 Slowest Key Easy C#, Java ✔️
1630 Arithmetic Subarrays Medium C# ✔️
1631 Path With Minimum Effort Medium C#, Java ✔️
1632 Rank Transform of a Matrix Hard C# ✔️
1633 Percentage of Users Attended a Contest Easy MySQL, SQLServer ✔️
1634 Add Two Polynomials Represented as Linked Lists Medium C# ✔️
1635 Hopper Company Queries I Hard MySQL, SQLServer ✔️
1636 Sort Array by Increasing Frequency Easy C# ✔️
1637 Widest Vertical Area Between Two Points Containing No Points Medium C# ✔️
1638 Count Substrings That Differ by One Character Medium C# ✔️
1639 Number of Ways to Form a Target String Given a Dictionary Hard ➖
1640 Check Array Formation Through Concatenation Easy C#, Java ✔️
1641 Count Sorted Vowel Strings Medium C# ✔️
1642 Furthest Building You Can Reach Medium C#, Java ✔️
1643 Kth Smallest Instructions Hard ➖
1644 Lowest Common Ancestor of a Binary Tree II Medium C# ✔️
1645 Hopper Company Queries II Hard MySQL, SQLServer ✔️
1646 Get Maximum in Generated Array Easy C# ✔️
1647 Minimum Deletions to Make Character Frequencies Unique Medium C# ✔️
1648 Sell Diminishing-Valued Colored Balls Medium ➖
1649 Create Sorted Array through Instructions Hard C# ✔️
1650 Lowest Common Ancestor of a Binary Tree III Medium C#, Java ✔️
1651 Hopper Company Queries III Hard MySQL, SQLServer ✔️
1652 Defuse the Bomb Easy C# ✔️
1653 Minimum Deletions to Make String Balanced Medium C# ✔️
1654 Minimum Jumps to Reach Home Medium C# ✔️
1655 Distribute Repeating Integers Hard ➖
1656 Design an Ordered Stream Easy C# ✔️
1657 Determine if Two Strings Are Close Medium C#, Java ✔️
1658 Minimum Operations to Reduce X to Zero Medium C# ✔️
1659 Maximize Grid Happiness Hard ➖
1660 Correct a Binary Tree Medium C#, Java ✔️
1661 Average Time of Process per Machine Easy MySQL, SQLServer ✔️
1662 Check If Two String Arrays are Equivalent Easy C# ✔️
1663 Smallest String With A Given Numeric Value Medium C#, Java ✔️
1664 Ways to Make a Fair Array Medium ➖
1665 Minimum Initial Energy to Finish Tasks Hard ➖
1666 Change the Root of a Binary Tree Medi