1 |
Two Sum |
Python |
Easy |
2 |
Add Two Numbers |
Python |
Medium |
3 |
Longest Substring Without Repeating Characters |
Python |
Medium |
4 |
Median of Two Sorted Arrays |
Python |
Hard |
5 |
Longest Palindromic Substring |
Python |
Medium |
6 |
ZigZag Conversion |
Python |
Medium |
7 |
Reverse Integer |
Python |
Easy |
8 |
String to Integer (atoi) |
Python |
Medium |
9 |
Palindrome Number |
Python |
Easy |
11 |
Container With Most Water |
Python |
Medium |
12 |
Integer to Roman |
Python |
Medium |
13 |
Roman to Integer |
Python |
Easy |
14 |
Longest Common Prefix |
Python |
Easy |
15 |
3Sum |
Python |
Medium |
16 |
3Sum Closest |
Python |
Medium |
17 |
Letter Combinations of a Phone Number |
Python |
Medium |
18 |
4Sum |
Python |
Medium |
19 |
Remove Nth Node From End of List |
Python |
Medium |
20 |
Valid Parentheses |
Python |
Easy |
21 |
Merge Two Sorted Lists |
Python |
Easy |
22 |
Generate Parentheses |
Python |
Medium |
24 |
Swap Nodes in Pairs |
Python |
Medium |
25 |
Reverse Nodes in k-Group |
Python |
Hard |
26 |
Remove Duplicates from Sorted Array |
Python |
Easy |
27 |
Remove Element |
Python |
Easy |
28 |
Implement strStr() |
Python |
Easy |
29 |
Divide Two Integers |
Python |
Medium |
31 |
Next Permutation |
Python |
Medium |
33 |
Search in Rotated Sorted Array |
Python |
Medium |
34 |
Find First and Last Position of Element in Sorted Array |
Python |
Medium |
35 |
Search Insert Position |
Python |
Easy |
36 |
Valid Sudoku |
Python |
Medium |
38 |
Count and Say |
Python |
Easy |
39 |
Combination Sum |
Python |
Medium |
40 |
Combination Sum II |
Python |
Medium |
43 |
Multiply Strings |
Python |
Medium |
46 |
Permutations |
Python |
Medium |
47 |
Permutations II |
Python |
Medium |
48 |
Rotate Image |
Python |
Medium |
49 |
Group Anagrams |
Python |
Medium |
50 |
Pow(x, n) |
Python |
Medium |
53 |
Maximum Subarray |
Python |
Easy |
54 |
Spiral Matrix |
Python |
Medium |
55 |
Jump Game |
Python |
Medium |
56 |
Merge Intervals |
Python |
Medium |
58 |
Length of Last Word |
Python |
Easy |
59 |
Spiral Matrix II |
Python |
Medium |
60 |
Permutation Sequence |
Python |
Medium |
61 |
Rotate List |
Python |
Medium |
62 |
Unique Paths |
Python |
Medium |
63 |
Unique Paths II |
Python |
Medium |
64 |
Minimum Path Sum |
Python |
Medium |
66 |
Plus One |
Python |
Easy |
67 |
Add Binary |
Python |
Easy |
69 |
Sqrt(x) |
Python |
Easy |
70 |
Climbing Stairs |
Python |
Easy |
71 |
Simplify Path |
Python |
Medium |
73 |
Set Matrix Zeroes |
Python |
Medium |
74 |
Search a 2D Matrix |
Python |
Medium |
75 |
Sort Colors |
Python |
Medium |
77 |
Combinations |
Python |
Medium |
78 |
Subsets |
Python |
Medium |
79 |
Word Search |
Python |
Medium |
80 |
Remove Duplicates from Sorted Array II |
Python |
Medium |
81 |
Search in Rotated Sorted Array II |
Python |
Medium |
82 |
Remove Duplicates from Sorted List II |
Python |
Medium |
83 |
Remove Duplicates from Sorted List |
Python |
Easy |
86 |
Partition List |
Python |
Medium |
88 |
Merge Sorted Array |
Python |
Easy |
89 |
Gray Code |
Python |
Medium |
90 |
Subsets II |
Python |
Medium |
91 |
Decode Ways |
Python |
Medium |
92 |
Reverse Linked List II |
Python |
Medium |
93 |
Restore IP Addresses |
Python |
Medium |
94 |
Binary Tree Inorder Traversal |
Python |
Medium |
100 |
Same Tree |
Python |
Easy |
101 |
Symmetric Tree |
Python |
Easy |
102 |
Binary Tree Level Order Traversal |
Python |
Medium |
103 |
Binary Tree Zigzag Level Order Traversal |
Python |
Medium |
104 |
Maximum Depth of Binary Tree |
Python |
Easy |
107 |
Binary Tree Level Order Traversal II |
Python |
Easy |
108 |
Convert Sorted Array to Binary Search Tree |
Python |
Easy |
110 |
Balanced Binary Tree |
Python |
Easy |
111 |
Minimum Depth of Binary Tree |
Python |
Easy |
112 |
Path Sum |
Python |
Easy |
118 |
Pascal's Triangle |
Python |
Easy |
119 |
Pascal's Triangle II |
Python |
Easy |
120 |
Triangle |
Python |
Medium |
121 |
Best Time to Buy and Sell Stock |
Python |
Easy |
122 |
Best Time to Buy and Sell Stock II |
Python |
Easy |
125 |
Valid Palindrome |
Python |
Easy |
136 |
Single Number |
Python |
Easy |
141 |
Linked List Cycle |
Python |
Easy |
144 |
Binary Tree Preorder Traversal |
Python |
Medium |
148 |
Sort List |
Python |
Medium |
155 |
Min Stack |
Python |
Easy |
157 |
Read N Characters Given Read4 |
Python |
Easy |
160 |
Intersection of Two Linked Lists |
Python |
Easy |
167 |
Two Sum II - Input array is sorted |
Python |
Easy |
168 |
Excel Sheet Column Title |
Python |
Easy |
169 |
Majority Element |
Python |
Easy |
170 |
Two Sum III - Data structure design |
Python |
Easy |
171 |
Excel Sheet Column Number |
Python |
Easy |
172 |
Factorial Trailing Zeroes |
Python |
Easy |
175 |
Combine Two Tables |
SQL |
Easy |
176 |
Second Highest Salary |
SQL |
Easy |
181 |
Employees Earning More Than Their Managers |
SQL |
Easy |
182 |
Duplicate Emails |
SQL |
Easy |
183 |
Customers Who Never Order |
SQL |
Easy |
189 |
Rotate Array |
Python |
Easy |
190 |
Reverse Bits |
Python |
Easy |
191 |
Number of 1 Bits |
Python |
Easy |
196 |
Delete Duplicate Emails |
SQL |
Easy |
197 |
Rising Temperature |
SQL |
Easy |
198 |
House Robber |
Python |
Easy |
200 |
Number of Islands |
Python |
Medium |
202 |
Happy Number |
Python |
Easy |
203 |
Remove Linked List Elements |
Python |
Easy |
204 |
Count Primes |
Python |
Easy |
205 |
Isomorphic Strings |
Python |
Easy |
206 |
Reverse Linked List |
Python |
Easy |
208 |
Implement Trie (Prefix Tree) |
Python |
Medium |
209 |
Minimum Size Subarray Sum |
Python |
Medium |
217 |
Contains Duplicate |
Python |
Easy |
219 |
Contains Duplicate II |
Python |
Easy |
225 |
Implement Stack using Queues |
Python |
Easy |
226 |
Invert Binary Tree |
Python |
Easy |
231 |
Power of Two |
Python |
Easy |
232 |
Implement Queue using Stacks |
Python |
Easy |
234 |
Palindrome Linked List |
Python |
Easy |
235 |
Lowest Common Ancestor of a Binary Search Tree |
Python |
Easy |
237 |
Delete Node in a Linked List |
Python |
Easy |
238 |
Product of Array Except Self |
Python |
Medium |
242 |
Valid Anagram |
Python |
Easy |
243 |
Shortest Word Distance |
Python |
Easy |
246 |
Strobogrammatic Number |
Python |
Easy |
252 |
Meeting Rooms |
Python |
Easy |
256 |
Paint House |
Python |
Easy |
257 |
Binary Tree Paths |
Python |
Easy |
258 |
Add Digits |
Python |
Easy |
261 |
Graph Valid Tree |
Python |
Medium |
263 |
Ugly Number |
Python |
Easy |
266 |
Palindrome Permutation |
Python |
Easy |
268 |
Missing Number |
Python |
Easy |
270 |
Closest Binary Search Tree Value |
Python |
Easy |
276 |
Paint Fence |
Python |
Easy |
278 |
First Bad Version |
Python |
Easy |
283 |
Move Zeroes |
Python |
Easy |
290 |
Word Pattern |
Python |
Easy |
292 |
Nim Game |
Python |
Easy |
293 |
Flip Game |
Python |
Easy |
303 |
Range Sum Query - Immutable |
Python |
Easy |
323 |
Number of Connected Components in an Undirected Graph |
Python |
Medium |
325 |
Maximum Size Subarray Sum Equals k |
Pyhon |
Medium |
326 |
Power of Three |
Python |
Easy |
339 |
Nested List Weight Sum |
Python |
Easy |
342 |
Power of Four |
Python |
Easy |
344 |
Reverse String |
Python |
Easy |
345 |
Reverse Vowels of a String |
Python |
Easy |
346 |
Moving Average from Data Stream |
Python |
Easy |
349 |
Intersection of Two Arrays |
Python |
Easy |
350 |
Intersection of Two Arrays II |
Python |
Easy |
359 |
Logger Rate Limiter |
Python |
Easy |
367 |
Valid Perfect Square |
Python |
Easy |
371 |
Sum of Two Integers |
Python |
Easy |
374 |
Guess Number Higher or Lower |
Python |
Easy |
383 |
Ransom Note |
Python |
Easy |
387 |
First Unique Character in a String |
Python |
Easy |
389 |
Find the Difference |
Python |
Easy |
400 |
Nth Digit |
Python |
Easy |
401 |
Binary Watch |
Python |
Easy |
404 |
Sum of Left Leaves |
Python |
Easy |
405 |
Convert a Number to Hexadecimal |
Python |
Easy |
408 |
Valid Word Abbreviation |
Python |
Easy |
409 |
Longest Palindrome |
Python |
Easy |
412 |
Fizz Buzz |
Python |
Easy |
414 |
Third Maximum Number |
Python |
Easy |
415 |
Add Strings |
Python |
Easy |
416 |
Partition Equal Subset Sum |
Python |
Medium |
422 |
Valid Word Square |
Python |
Easy |
427 |
Construct Quad Tree |
Python |
Easy |
429 |
N-ary Tree Level Order Traversal |
Python |
Easy |
434 |
Number of Segments in a String |
Python |
Easy |
437 |
Path Sum III |
Python |
Easy |
438 |
Find All Anagrams in a String |
Python |
Easy |
441 |
Arranging Coins |
Python |
Easy |
443 |
String Compression |
Python |
Easy |
447 |
Number of Boomerangs |
Python |
Easy |
448 |
Find All Numbers Disappeared in an Array |
Python |
Easy |
453 |
Minimum Moves to Equal Array Elements |
Python |
Easy |
455 |
Assign Cookies |
Python |
Easy |
458 |
Poor Pigs |
Python |
Easy |
459 |
Repeated Substring Pattern |
Python |
Easy |
461 |
Hamming Distance |
Python |
Easy |
463 |
Island Perimeter |
Python |
Easy |
468 |
Validate IP Address |
Python |
Medium |
475 |
Heaters |
Python |
Easy |
476 |
Number Complement |
Python |
Easy |
479 |
Largest Palindrome Product |
Python |
Easy |
482 |
License Key Formatting |
Python |
Easy |
485 |
Max Consecutive Ones |
Python |
Easy |
492 |
Construct the Rectangle |
Python |
Easy |
496 |
Next Greater Element I |
Python |
Easy |
500 |
Keyboard Row |
Python |
Easy |
501 |
Find Mode in Binary Search Tree |
Python |
Easy |
504 |
Base 7 |
Python |
Easy |
506 |
Relative Ranks |
Python |
Easy |
507 |
Perfect Number |
Python |
Easy |
520 |
Detect Capital |
Python |
Easy |
521 |
Longest Uncommon Subsequence I |
Python |
Easy |
530 |
Minimum Absolute Difference in BST |
Python |
Easy |
532 |
K-diff Pairs in an Array |
Python |
Easy |
538 |
Convert BST to Greater Tree |
Python |
Easy |
541 |
Reverse String II |
Python |
Easy |
543 |
Diameter of Binary Tree |
Python |
Easy |
551 |
Student Attendance Record I |
Python |
Easy |
557 |
Reverse Words in a String III |
Python |
Easy |
558 |
Quad Tree Intersection |
Python |
Easy |
559 |
Maximum Depth of N-ary Tree |
Python |
Easy |
560 |
Subarray Sum Equals K |
Python |
Medium |
561 |
Array Partition I |
Python |
Easy |
563 |
Binary Tree Tilt |
Python |
Easy |
566 |
Reshape the Matrix |
Python |
Easy |
572 |
Subtree of Another Tree |
Python |
Easy |
575 |
Distribute Candies |
Python |
Easy |
577 |
Employee Bonus |
SQL |
Easy |
581 |
Shortest Unsorted Continuous Subarray |
Python |
Easy |
584 |
Find Customer Referee |
SQL |
Easy |
586 |
Customer Placing the Largest Number of Orders |
SQL |
Easy |
589 |
N-ary Tree Preorder Traversal |
Python |
Easy |
590 |
N-ary Tree Postorder Traversal |
Python |
Easy |
594 |
Longest Harmonious Subsequence |
Python |
Easy |
595 |
Big Countries |
SQL |
Easy |
596 |
Classes More Than 5 Students |
SQL |
Easy |
597 |
Friend Requests I: Overall Acceptance Rate |
SQL |
Easy |
598 |
Range Addition II |
Python |
Easy |
599 |
Minimum Index Sum of Two Lists |
Python |
Easy |
603 |
Consecutive Available Seats |
SQL |
Easy |
604 |
Design Compressed String Iterator |
Python |
Easy |
605 |
Can Place Flowers |
Python |
Easy |
606 |
Construct String from Binary Tree |
Python |
Easy |
607 |
Sales Person |
SQL |
Easy |
610 |
Triangle Judgement |
SQL |
Easy |
613 |
Shortest Distance in a Line |
SQL |
Easy |
617 |
Merge Two Binary Trees |
Python |
Easy |
619 |
Biggest Single Number |
SQL |
Easy |
620 |
Not Boring Movies |
SQL |
Easy |
624 |
Maximum Distance in Arrays |
Python |
Easy |
627 |
Swap Salary |
SQL |
Easy |
628 |
Maximum Product of Three Numbers |
Python |
Easy |
633 |
Sum of Square Numbers |
Python |
Easy |
637 |
Average of Levels in Binary Tree |
Python |
Easy |
643 |
Maximum Average Subarray I |
Python |
Easy |
645 |
Set Mismatch |
Python |
Easy |
653 |
Two Sum IV - Input is a BST |
Python |
Easy |
657 |
Robot Return to Origin |
Python |
Easy |
661 |
Image Smoother |
Python |
Easy |
665 |
Non-decreasing Array |
Python |
Easy |
669 |
Trim a Binary Search Tree |
Python |
Easy |
671 |
Second Minimum Node In a Binary Tree |
Python |
Easy |
674 |
Longest Continuous Increasing Subsequence |
Python |
Easy |
680 |
Valid Palindrome II |
Python |
Easy |
682 |
Baseball Game |
Python |
Easy |
686 |
Repeated String Match |
Python |
Easy |
687 |
Longest Univalue Path |
Python |
Easy |
690 |
Employee Importance |
Python |
Easy |
693 |
Binary Number with Alternating Bits |
Python |
Easy |
695 |
Max Area of Island |
Python |
Easy |
696 |
Count Binary Substrings |
Python |
Easy |
713 |
Subarray Product Less Than K |
Python |
Medium |
987 |
Vertical Order Traversal of a Binary Tree |
Python |
Medium |
1052 |
Grumpy Bookstore Owner |
Python |
Medium |
1151 |
Minimum Swaps to Group All 1's Together |
Python |
Medium |
1155 |
Number of Dice Nolls with Target Sum |
Python |
Medium |
1197 |
Minimum Knight Moves |
Python |
Medium |
1245 |
Tree Diameter |
Python |
Medium |
1492 |
The kth Factor of n |
Python |
Medium |
1676 |
Lowest Common Ancestor of a Binary Tree IV |
Python |
Medium |
2355 |
Maximum Number of Books You Can Take |
Python |
Hard |
2405 |
Optimal Partition of String |
Python |
Medium |
2422 |
Merge Operations to Turn Array Into a Palindrome |
Python |
Medium |
2534 |
Time Taken to Cross the Door |
Python |
Hard |