/leetcode-solutions

leetcode-implementation

Primary LanguageRuby

Leetcode

Now start to work on leetcode for fun.

Using ruby to start because ruby looks like a elegant language.

I have solved 97 / 645 problems while 120 problems are still locked.

Good reference

repository for reference

leetcode-ruby leetcode

mostly in javascript:

LeetCode-Solutions

in go:

Leetcode-go

Chart

This part is generated by generator.js

Leetcode Solutions chart generated with JavaScript

Update time: Sun Apr 01 2018 18:04:37 GMT+0800 (CST)

I have solved 104 / 726 problems while 133 problems are still locked.

(Notes: 📘 means you need to buy a book from Leetcode)

# Title Source Code Explanation Difficulty
829 Subdomain Visit Count Easy
828 Chalkboard XOR Game Hard
827 Expressive Words Medium
826 Soup Servings Medium
825 Max Increase to Keep City Skyline Medium
824 Number of Lines To Write String Easy
823 Split Array With Same Average Hard
822 Unique Morse Code Words Easy
821 Bricks Falling When Hit Hard
820 Find Eventual Safe States Medium
819 Minimum Swaps To Make Sequences Increasing Medium
818 Similar RGB Color 📘 Easy
815 Champagne Tower Medium
814 Smallest Rotation with Highest Score Hard
813 All Paths From Source to Target Medium
812 Rotate String Easy
811 Number of Subarrays with Bounded Maximum Medium
810 Valid Tic-Tac-Toe State Medium
809 Preimage Size of Factorial Zeroes Function Hard
808 Number of Matching Subsequences Medium
807 Custom Sort String Medium
806 Domino and Tromino Tiling Medium
805 Escape The Ghosts Medium
804 Rotated Digits Easy
803 Cheapest Flights Within K Stops Medium
802 K-th Smallest Prime Fraction Hard
801 Is Graph Bipartite? Medium
800 Letter Case Permutation Easy
799 Minimum Distance Between BST Nodes Easy
798 Transform to Chessboard Hard
797 Rabbits in Forest Medium
796 Reaching Points Hard
795 K-th Symbol in Grammar Medium
794 Swim in Rising Water Hard
793 Swap Adjacent in LR String Medium
791 Split BST 📘 Medium
790 Global and Local Inversions Medium
788 Minimize Max Distance to Gas Station 📘 Hard
787 Sliding Puzzle Hard
785 Basic Calculator III 📘 Hard
782 Jewels and Stones Easy
781 Basic Calculator IV Hard
780 Max Chunks To Make Sorted Medium
779 Max Chunks To Make Sorted II Hard
778 Reorganize String Medium
777 Toeplitz Matrix Easy
770 Couples Holding Hands Hard
769 Largest Plus Sign Medium
768 Partition Labels Medium
767 Prime Number of Set Bits in Binary Representation Easy
763 Special Binary String Hard
762 Find Anagram Mappings 📘 Easy
761 Employee Free Time 📘 Hard
760 Bold Words in String 📘 Easy
759 Set Intersection Size At Least Two Hard
757 Pyramid Transition Matrix Medium
756 Pour Water 📘 Medium
755 Reach a Number Medium
754 Cracking the Safe Hard
753 Open the Lock Medium
752 IP to CIDR 📘 Easy
751 Number Of Corner Rectangles 📘 Medium
750 Contain Virus Hard
749 Shortest Completing Word Medium
748 Largest Number At Least Twice of Others Easy
747 Min Cost Climbing Stairs Easy
746 Prefix and Suffix Search Hard
745 Find Smallest Letter Greater Than Target Easy
744 Network Delay Time Medium
743 Closest Leaf in a Binary Tree 📘 Medium
741 Cherry Pickup Hard
740 Delete and Earn Medium
739 Daily Temperatures Medium
738 Monotone Increasing Digits Medium
737 Sentence Similarity II 📘 Medium
736 Parse Lisp Expression Hard
735 Asteroid Collision Medium
734 Sentence Similarity 📘 Easy
733 Flood Fill Easy
732 My Calendar III Hard
731 My Calendar II Medium
730 Count Different Palindromic Subsequences Hard
729 My Calendar I Medium
728 Self Dividing Numbers Easy
727 Minimum Window Subsequence 📘 Hard
726 Number of Atoms Hard
725 Split Linked List in Parts Medium
724 Find Pivot Index Easy
723 Candy Crush 📘 Medium
722 Remove Comments Medium
721 Accounts Merge Medium
720 Longest Word in Dictionary javascript Easy
719 Find K-th Smallest Pair Distance Hard
718 Maximum Length of Repeated Subarray Medium
717 1-bit and 2-bit Characters Easy
716 Max Stack 📘 Hard
715 Range Module Hard
714 Best Time to Buy and Sell Stock with Transaction Fee Medium
713 Subarray Product Less Than K Medium
712 Minimum ASCII Delete Sum for Two Strings Medium
711 Number of Distinct Islands II 📘 Hard
699 Falling Squares Hard
698 Partition to K Equal Sum Subsets Medium
697 Degree of an Array Easy
696 Count Binary Substrings Easy
695 Max Area of Island Easy
694 Number of Distinct Islands 📘 Medium
693 Binary Number with Alternating Bits Easy
692 Top K Frequent Words Medium
691 Stickers to Spell Word Hard
690 Employee Importance Easy
689 Maximum Sum of 3 Non-Overlapping Subarrays Hard
688 Knight Probability in Chessboard Medium
687 Longest Univalue Path Easy
686 Repeated String Match Easy
685 Redundant Connection II Hard
684 Redundant Connection Medium
683 K Empty Slots 📘 Hard
682 Baseball Game Easy
681 Next Closest Time 📘 Medium
680 Valid Palindrome II Easy
679 24 Game Hard
678 Valid Parenthesis String Medium
677 Map Sum Pairs Medium
676 Implement Magic Dictionary Medium
675 Cut Off Trees for Golf Event Hard
674 Longest Continuous Increasing Subsequence Easy
673 Number of Longest Increasing Subsequence Medium
672 Bulb Switcher II Medium
671 Second Minimum Node In a Binary Tree Easy
670 Maximum Swap Medium
669 Trim a Binary Search Tree Easy
668 Kth Smallest Number in Multiplication Table Hard
667 Beautiful Arrangement II Medium
666 Path Sum IV 📘 Medium
665 Non-decreasing Array Easy
664 Strange Printer Hard
663 Equal Tree Partition 📘 Medium
662 Maximum Width of Binary Tree Medium
661 Image Smoother Easy
660 Remove 9 📘 Hard
659 Split Array into Consecutive Subsequences Medium
658 Find K Closest Elements Medium
657 Judge Route Circle Easy
656 Coin Path 📘 Hard
655 Print Binary Tree Medium
654 Maximum Binary Tree Medium
653 Two Sum IV - Input is a BST Easy
652 Find Duplicate Subtrees Medium
651 4 Keys Keyboard 📘 Medium
650 2 Keys Keyboard Medium
649 Dota2 Senate Medium
648 Replace Words Medium
647 Palindromic Substrings ruby Medium
646 Maximum Length of Pair Chain Medium
645 Set Mismatch Easy
644 Maximum Average Subarray II 📘 Hard
643 Maximum Average Subarray I Easy
642 Design Search Autocomplete System 📘 Hard
640 Solve the Equation Medium
639 Decode Ways II Hard
638 Shopping Offers Medium
637 Average of Levels in Binary Tree Easy
636 Exclusive Time of Functions Medium
635 Design Log Storage System 📘 Medium
634 Find the Derangement of An Array 📘 Medium
633 Sum of Square Numbers Easy
632 Smallest Range Hard
631 Design Excel Sum Formula 📘 Hard
630 Course Schedule III Hard
629 K Inverse Pairs Array Hard
628 Maximum Product of Three Numbers Easy
625 Minimum Factorization 📘 Medium
624 Maximum Distance in Arrays 📘 Easy
623 Add One Row to Tree javascript Medium
621 Task Scheduler Medium
617 Merge Two Binary Trees Easy
616 Add Bold Tag in String 📘 Medium
611 Valid Triangle Number ruby Medium
609 Find Duplicate File in System Medium
606 Construct String from Binary Tree ruby Easy
605 Can Place Flowers Easy
604 Design Compressed String Iterator 📘 Easy
600 Non-negative Integers without Consecutive Ones Hard
599 Minimum Index Sum of Two Lists go Easy
598 Range Addition II ruby Easy
594 Longest Harmonious Subsequence Easy
593 Valid Square Medium
592 Fraction Addition and Subtraction Medium
591 Tag Validator Hard
588 Design In-Memory File System 📘 Hard
587 Erect the Fence Hard
583 Delete Operation for Two Strings Medium
582 Kill Process 📘 Medium
581 Shortest Unsorted Continuous Subarray Easy
576 Out of Boundary Paths Medium
575 Distribute Candies Easy
573 Squirrel Simulation 📘 Medium
572 Subtree of Another Tree Easy
568 Maximum Vacation Days 📘 Hard
567 Permutation in String Medium
566 Reshape the Matrix Easy
565 Array Nesting Medium
564 Find the Closest Palindrome Hard
563 Binary Tree Tilt Easy
562 Longest Line of Consecutive One in Matrix 📘 Medium
561 Array Partition I Easy
560 Subarray Sum Equals K ruby Medium
557 Reverse Words in a String III Easy
556 Next Greater Element III ruby Medium
555 Split Concatenated Strings 📘 Medium
554 Brick Wall ruby Medium
553 Optimal Division Medium
552 Student Attendance Record II Hard
551 Student Attendance Record I Easy
549 Binary Tree Longest Consecutive Sequence II 📘 Medium
548 Split Array with Equal Sum 📘 Medium
547 Friend Circles Medium
546 Remove Boxes Hard
545 Boundary of Binary Tree 📘 Medium
544 Output Contest Matches 📘 Medium
543 Diameter of Binary Tree Easy
542 01 Matrix ruby Medium
541 Reverse String II Easy
540 Single Element in a Sorted Array ruby Medium
539 Minimum Time Difference Medium
538 Convert BST to Greater Tree Easy
537 Complex Number Multiplication Medium
536 Construct Binary Tree from String 📘 Medium
535 Encode and Decode TinyURL Medium
533 Lonely Pixel II 📘 Medium
532 K-diff Pairs in an Array Easy
531 Lonely Pixel I 📘 Medium
530 Minimum Absolute Difference in BST Easy
529 Minesweeper Medium
527 Word Abbreviation 📘 Hard
526 Beautiful Arrangement Medium
525 Contiguous Array Medium
524 Longest Word in Dictionary through Deleting Medium
523 Continuous Subarray Sum Medium
522 Longest Uncommon Subsequence II Medium
521 Longest Uncommon Subsequence I Easy
520 Detect Capital javascript go Easy
517 Super Washing Machines Hard
516 Longest Palindromic Subsequence Medium
515 Find Largest Value in Each Tree Row Medium
514 Freedom Trail Hard
513 Find Bottom Left Tree Value ruby Medium
508 Most Frequent Subtree Sum Medium
507 Perfect Number Easy
506 Relative Ranks Easy
505 The Maze II 📘 Medium
504 Base 7 Easy
503 Next Greater Element II ruby Medium
502 IPO Hard
501 Find Mode in Binary Search Tree Easy
500 Keyboard Row Easy
499 The Maze III 📘 Hard
498 Diagonal Traverse Medium
496 Next Greater Element I Easy
495 Teemo Attacking Medium
494 Target Sum Medium
493 Reverse Pairs Hard
492 Construct the Rectangle ruby Easy
491 Increasing Subsequences Medium
490 The Maze 📘 Medium
488 Zuma Game Hard
487 Max Consecutive Ones II 📘 Medium
486 Predict the Winner Medium
485 Max Consecutive Ones javascript Easy
484 Find Permutation 📘 Medium
483 Smallest Good Base ruby Hard
482 License Key Formatting Easy
481 Magical String Medium
480 Sliding Window Median Hard
479 Largest Palindrome Product Easy
477 Total Hamming Distance Medium
476 Number Complement Easy
475 Heaters Easy
474 Ones and Zeroes Medium
473 Matchsticks to Square Medium
472 Concatenated Words Hard
471 Encode String with Shortest Length 📘 Hard
469 Convex Polygon 📘 Medium
468 Validate IP Address Medium
467 Unique Substrings in Wraparound String Medium
466 Count The Repetitions Hard
465 Optimal Account Balancing 📘 Hard
464 Can I Win Medium
463 Island Perimeter Easy
462 Minimum Moves to Equal Array Elements II Medium
461 Hamming Distance Easy
460 LFU Cache Hard
459 Repeated Substring Pattern Easy
456 132 Pattern Medium
455 Assign Cookies Easy
454 4Sum II Medium
453 Minimum Moves to Equal Array Elements Easy
452 Minimum Number of Arrows to Burst Balloons Medium
451 Sort Characters By Frequency ruby Medium
450 Delete Node in a BST ruby Medium
449 Serialize and Deserialize BST ruby Medium
448 Find All Numbers Disappeared in an Array Easy
447 Number of Boomerangs Easy
446 Arithmetic Slices II - Subsequence Hard
445 Add Two Numbers II ruby Medium
444 Sequence Reconstruction 📘 Medium
443 String Compression Easy
442 Find All Duplicates in an Array ruby Medium
441 Arranging Coins Easy
440 K-th Smallest in Lexicographical Order Hard
439 Ternary Expression Parser 📘 Medium
438 Find All Anagrams in a String Easy
437 Path Sum III ruby Easy
436 Find Right Interval Medium
435 Non-overlapping Intervals Medium
434 Number of Segments in a String Easy
432 All O`one Data Structure Hard
425 Word Squares 📘 Hard
424 Longest Repeating Character Replacement Medium
423 Reconstruct Original Digits from English Medium
422 Valid Word Square 📘 Easy
421 Maximum XOR of Two Numbers in an Array Medium
420 Strong Password Checker Hard
419 Battleships in a Board Medium
418 Sentence Screen Fitting 📘 Medium
417 Pacific Atlantic Water Flow Medium
416 Partition Equal Subset Sum Medium
415 Add Strings Easy
414 Third Maximum Number Easy
413 Arithmetic Slices Medium
412 Fizz Buzz Easy
411 Minimum Unique Word Abbreviation 📘 Hard
410 Split Array Largest Sum Hard
409 Longest Palindrome Easy
408 Valid Word Abbreviation 📘 Easy
407 Trapping Rain Water II Hard
406 Queue Reconstruction by Height Medium
405 Convert a Number to Hexadecimal Easy
404 Sum of Left Leaves Easy
403 Frog Jump Hard
402 Remove K Digits ruby Medium
401 Binary Watch ruby Easy
400 Nth Digit Easy
399 Evaluate Division Medium
398 Random Pick Index Medium
397 Integer Replacement Medium
396 Rotate Function Medium
395 Longest Substring with At Least K Repeating Characters Medium
394 Decode String go Medium
393 UTF-8 Validation Medium
392 Is Subsequence Medium
391 Perfect Rectangle Hard
390 Elimination Game Medium
389 Find the Difference Easy
388 Longest Absolute File Path Medium
387 First Unique Character in a String Easy
386 Lexicographical Numbers Medium
385 Mini Parser Medium
384 Shuffle an Array Medium
383 Ransom Note Easy
382 Linked List Random Node Medium
381 Insert Delete GetRandom O(1) - Duplicates allowed Hard
380 Insert Delete GetRandom O(1) Medium
379 Design Phone Directory 📘 Medium
378 Kth Smallest Element in a Sorted Matrix Medium
377 Combination Sum IV Medium
376 Wiggle Subsequence Medium
375 Guess Number Higher or Lower II Medium
374 Guess Number Higher or Lower Easy
373 Find K Pairs with Smallest Sums Medium
372 Super Pow Medium
371 Sum of Two Integers Easy
370 Range Addition 📘 Medium
369 Plus One Linked List 📘 Medium
368 Largest Divisible Subset Medium
367 Valid Perfect Square Easy
366 Find Leaves of Binary Tree 📘 Medium
365 Water and Jug Problem Medium
364 Nested List Weight Sum II 📘 Medium
363 Max Sum of Rectangle No Larger Than K Hard
362 Design Hit Counter 📘 Medium
361 Bomb Enemy 📘 Medium
360 Sort Transformed Array 📘 Medium
359 Logger Rate Limiter 📘 Easy
358 Rearrange String k Distance Apart 📘 Hard
357 Count Numbers with Unique Digits ruby Medium
356 Line Reflection 📘 Medium
355 Design Twitter Medium
354 Russian Doll Envelopes Hard
353 Design Snake Game 📘 Medium
352 Data Stream as Disjoint Intervals Hard
351 Android Unlock Patterns 📘 Medium
350 Intersection of Two Arrays II Easy
349 Intersection of Two Arrays Easy
348 Design Tic-Tac-Toe 📘 Medium
347 Top K Frequent Elements Medium
346 Moving Average from Data Stream 📘 Easy
345 Reverse Vowels of a String Easy
344 Reverse String ruby Easy
343 Integer Break ruby Medium
342 Power of Four Easy
341 Flatten Nested List Iterator Medium
340 Longest Substring with At Most K Distinct Characters 📘 Hard
339 Nested List Weight Sum 📘 Easy
338 Counting Bits ruby Medium
337 House Robber III ruby Medium
336 Palindrome Pairs Hard
335 Self Crossing Hard
334 Increasing Triplet Subsequence Medium
333 Largest BST Subtree 📘 Medium
332 Reconstruct Itinerary Medium
331 Verify Preorder Serialization of a Binary Tree ruby Medium
330 Patching Array Hard
329 Longest Increasing Path in a Matrix Hard
328 Odd Even Linked List ruby Medium
327 Count of Range Sum Hard
326 Power of Three ruby Easy
325 Maximum Size Subarray Sum Equals k 📘 Medium
324 Wiggle Sort II Medium
323 Number of Connected Components in an Undirected Graph 📘 Medium
322 Coin Change Medium
321 Create Maximum Number Hard
320 Generalized Abbreviation 📘 Medium
319 Bulb Switcher Medium
318 Maximum Product of Word Lengths Medium
317 Shortest Distance from All Buildings 📘 Hard
316 Remove Duplicate Letters Hard
315 Count of Smaller Numbers After Self Hard
314 Binary Tree Vertical Order Traversal 📘 Medium
313 Super Ugly Number ruby Medium
312 Burst Balloons Hard
311 Sparse Matrix Multiplication 📘 Medium
310 Minimum Height Trees Medium
309 Best Time to Buy and Sell Stock with Cooldown Medium
308 Range Sum Query 2D - Mutable 📘 Hard
307 Range Sum Query - Mutable Medium
306 Additive Number Medium
305 Number of Islands II 📘 Hard
304 Range Sum Query 2D - Immutable Medium
303 Range Sum Query - Immutable ruby Easy
302 Smallest Rectangle Enclosing Black Pixels 📘 Hard
301 Remove Invalid Parentheses Hard
300 Longest Increasing Subsequence Medium
299 Bulls and Cows Medium
298 Binary Tree Longest Consecutive Sequence 📘 Medium
297 Serialize and Deserialize Binary Tree ruby Hard
296 Best Meeting Point 📘 Hard
295 Find Median from Data Stream Hard
294 Flip Game II 📘 Medium
293 Flip Game 📘 Easy
292 Nim Game Easy
291 Word Pattern II 📘 Hard
290 Word Pattern Easy
289 Game of Life Medium
288 Unique Word Abbreviation 📘 Medium
287 Find the Duplicate Number ruby Medium
286 Walls and Gates 📘 Medium
285 Inorder Successor in BST 📘 Medium
284 Peeking Iterator Medium
283 Move Zeroes Easy
282 Expression Add Operators Hard
281 Zigzag Iterator 📘 Medium
280 Wiggle Sort 📘 Medium
279 Perfect Squares Medium
278 First Bad Version ruby Easy
277 Find the Celebrity 📘 Medium
276 Paint Fence 📘 Easy
275 H-Index II Medium
274 H-Index Medium
273 Integer to English Words Hard
272 Closest Binary Search Tree Value II 📘 Hard
271 Encode and Decode Strings 📘 Medium
270 Closest Binary Search Tree Value 📘 Easy
269 Alien Dictionary 📘 Hard
268 Missing Number Easy
267 Palindrome Permutation II 📘 Medium
266 Palindrome Permutation 📘 Easy
265 Paint House II 📘 Hard
264 Ugly Number II ruby Medium
263 Ugly Number ruby Easy
261 Graph Valid Tree 📘 Medium
260 Single Number III Medium
259 3Sum Smaller 📘 Medium
258 Add Digits Easy
257 Binary Tree Paths Easy
256 Paint House 📘 Easy
255 Verify Preorder Sequence in Binary Search Tree 📘 Medium
254 Factor Combinations 📘 Medium
253 Meeting Rooms II 📘 Medium
252 Meeting Rooms 📘 Easy
251 Flatten 2D Vector 📘 Medium
250 Count Univalue Subtrees 📘 Medium
249 Group Shifted Strings 📘 Medium
248 Strobogrammatic Number III 📘 Hard
247 Strobogrammatic Number II 📘 Medium
246 Strobogrammatic Number 📘 Easy
245 Shortest Word Distance III 📘 Medium
244 Shortest Word Distance II 📘 Medium
243 Shortest Word Distance 📘 Easy
242 Valid Anagram ruby Easy
241 Different Ways to Add Parentheses Medium
240 Search a 2D Matrix II ruby Medium
239 Sliding Window Maximum Hard
238 Product of Array Except Self Medium
237 Delete Node in a Linked List Easy
236 Lowest Common Ancestor of a Binary Tree ruby Medium
235 Lowest Common Ancestor of a Binary Search Tree ruby Easy
234 Palindrome Linked List Easy
233 Number of Digit One Hard
232 Implement Queue using Stacks Easy
231 Power of Two Easy
230 Kth Smallest Element in a BST ruby Medium
229 Majority Element II ruby Medium
228 Summary Ranges javascript Medium
227 Basic Calculator II Medium
226 Invert Binary Tree Easy
225 Implement Stack using Queues Easy
224 Basic Calculator ruby Hard
223 Rectangle Area Medium
222 Count Complete Tree Nodes ruby Medium
221 Maximal Square Medium
220 Contains Duplicate III Medium
219 Contains Duplicate II ruby Easy
218 The Skyline Problem Hard
217 Contains Duplicate Easy
216 Combination Sum III Medium
215 Kth Largest Element in an Array ruby Medium
214 Shortest Palindrome Hard
213 House Robber II Medium
212 Word Search II Hard
211 Add and Search Word - Data structure design Medium
210 Course Schedule II Medium
209 Minimum Size Subarray Sum ruby Medium
208 Implement Trie (Prefix Tree) Medium
207 Course Schedule Medium
206 Reverse Linked List Easy
205 Isomorphic Strings Easy
204 Count Primes Easy
203 Remove Linked List Elements Easy
202 Happy Number ruby Easy
201 Bitwise AND of Numbers Range Medium
200 Number of Islands Medium
199 Binary Tree Right Side View ruby Medium
198 House Robber Easy
191 Number of 1 Bits ruby Easy
190 Reverse Bits Easy
189 Rotate Array Easy
188 Best Time to Buy and Sell Stock IV Hard
187 Repeated DNA Sequences Medium
186 Reverse Words in a String II 📘 Medium
179 Largest Number Medium
174 Dungeon Game ruby Hard
173 Binary Search Tree Iterator Medium
172 Factorial Trailing Zeroes ruby Easy
171 Excel Sheet Column Number Easy
170 Two Sum III - Data structure design 📘 Easy
169 Majority Element Easy
168 Excel Sheet Column Title Easy
167 Two Sum II - Input array is sorted ruby Easy
166 Fraction to Recurring Decimal ruby Medium
165 Compare Version Numbers Medium
164 Maximum Gap ruby Hard
163 Missing Ranges 📘 Medium
162 Find Peak Element ruby Medium
161 One Edit Distance 📘 Medium
160 Intersection of Two Linked Lists javascript Easy
159 Longest Substring with At Most Two Distinct Characters 📘 Hard
158 Read N Characters Given Read4 II - Call multiple times 📘 Hard
157 Read N Characters Given Read4 📘 Easy
156 Binary Tree Upside Down 📘 Medium
155 Min Stack Easy
154 Find Minimum in Rotated Sorted Array II ruby Hard
153 Find Minimum in Rotated Sorted Array ruby Medium
152 Maximum Product Subarray Medium
151 Reverse Words in a String Medium
150 Evaluate Reverse Polish Notation ruby Medium
149 Max Points on a Line Hard
148 Sort List ruby Medium
147 Insertion Sort List Medium
146 LRU Cache Hard
145 Binary Tree Postorder Traversal Hard
144 Binary Tree Preorder Traversal ruby Medium
143 Reorder List Medium
142 Linked List Cycle II Medium
141 Linked List Cycle Easy
140 Word Break II Hard
139 Word Break Medium
138 Copy List with Random Pointer Medium
137 Single Number II Medium
136 Single Number Easy
135 Candy Hard
134 Gas Station Medium
133 Clone Graph Medium
132 Palindrome Partitioning II Hard
131 Palindrome Partitioning ruby Medium
130 Surrounded Regions Medium
129 Sum Root to Leaf Numbers Medium
128 Longest Consecutive Sequence ruby Hard
127 Word Ladder Medium
126 Word Ladder II Hard
125 Valid Palindrome Easy
124 Binary Tree Maximum Path Sum Hard
123 Best Time to Buy and Sell Stock III Hard
122 Best Time to Buy and Sell Stock II Easy
121 Best Time to Buy and Sell Stock Easy
120 Triangle Medium
119 Pascal's Triangle II Easy
118 Pascal's Triangle Easy
117 Populating Next Right Pointers in Each Node II Medium
116 Populating Next Right Pointers in Each Node Medium
115 Distinct Subsequences Hard
114 Flatten Binary Tree to Linked List ruby Medium
113 Path Sum II Medium
112 Path Sum Easy
111 Minimum Depth of Binary Tree ruby Easy
110 Balanced Binary Tree ruby Easy
109 Convert Sorted List to Binary Search Tree Medium
108 Convert Sorted Array to Binary Search Tree ruby Easy
107 Binary Tree Level Order Traversal II ruby Easy
106 Construct Binary Tree from Inorder and Postorder Traversal Medium
105 Construct Binary Tree from Preorder and Inorder Traversal Medium
104 Maximum Depth of Binary Tree Easy
103 Binary Tree Zigzag Level Order Traversal Medium
102 Binary Tree Level Order Traversal Medium
101 Symmetric Tree ruby Easy
100 Same Tree Easy
99 Recover Binary Search Tree Hard
98 Validate Binary Search Tree Medium
97 Interleaving String Hard
96 Unique Binary Search Trees ruby Medium
95 Unique Binary Search Trees II Medium
94 Binary Tree Inorder Traversal Medium
93 Restore IP Addresses Medium
92 Reverse Linked List II Medium
91 Decode Ways Medium
90 Subsets II ruby Medium
89 Gray Code ruby Medium
88 Merge Sorted Array Easy
87 Scramble String Hard
86 Partition List Medium
85 Maximal Rectangle Hard
84 Largest Rectangle in Histogram Hard
83 Remove Duplicates from Sorted List Easy
82 Remove Duplicates from Sorted List II Medium
81 Search in Rotated Sorted Array II Medium
80 Remove Duplicates from Sorted Array II Medium
79 Word Search Medium
78 Subsets ruby Medium
77 Combinations Medium
76 Minimum Window Substring Hard
75 Sort Colors Medium
74 Search a 2D Matrix ruby Medium
73 Set Matrix Zeroes Medium
72 Edit Distance Hard
71 Simplify Path Medium
70 Climbing Stairs ruby Easy
69 Sqrt(x) Easy
68 Text Justification Hard
67 Add Binary Easy
66 Plus One ruby Easy
65 Valid Number Hard
64 Minimum Path Sum Medium
63 Unique Paths II Medium
62 Unique Paths Medium
61 Rotate List ruby Medium
60 Permutation Sequence Medium
59 Spiral Matrix II Medium
58 Length of Last Word Easy
57 Insert Interval Hard
56 Merge Intervals Medium
55 Jump Game Medium
54 Spiral Matrix Medium
53 Maximum Subarray Easy
52 N-Queens II Hard
51 N-Queens ruby Hard
50 Pow(x, n) Medium
49 Group Anagrams Medium
48 Rotate Image Medium
47 Permutations II Medium
46 Permutations Medium
45 Jump Game II Hard
44 Wildcard Matching Hard
43 Multiply Strings Medium
42 Trapping Rain Water Hard
41 First Missing Positive Hard
40 Combination Sum II Medium
39 Combination Sum Medium
38 Count and Say Easy
37 Sudoku Solver Hard
36 Valid Sudoku Medium
35 Search Insert Position Easy
34 Search for a Range Medium
33 Search in Rotated Sorted Array Medium
32 Longest Valid Parentheses ruby Hard
31 Next Permutation Medium
30 Substring with Concatenation of All Words Hard
29 Divide Two Integers Medium
28 Implement strStr() ruby Easy
27 Remove Element Easy
26 Remove Duplicates from Sorted Array ruby Easy
25 Reverse Nodes in k-Group Hard
24 Swap Nodes in Pairs Medium
23 Merge k Sorted Lists Hard
22 Generate Parentheses Medium
21 Merge Two Sorted Lists Easy
20 Valid Parentheses Easy
19 Remove Nth Node From End of List ruby Medium
18 4Sum ruby Medium
17 Letter Combinations of a Phone Number Medium
16 3Sum Closest javascript Medium
15 3Sum Medium
14 Longest Common Prefix ruby Easy
13 Roman to Integer Easy
12 Integer to Roman ruby Medium
11 Container With Most Water Medium
10 Regular Expression Matching Hard
9 Palindrome Number Easy
8 String to Integer (atoi) ruby Medium
7 Reverse Integer ruby Easy
6 ZigZag Conversion Medium
5 Longest Palindromic Substring Medium
4 Median of Two Sorted Arrays Hard
3 Longest Substring Without Repeating Characters ruby go Medium
2 Add Two Numbers Medium
1 Two Sum ruby Easy