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解题报告

分类

难度


684  Redundant Connection  Algorithms  Medium  
683  K Empty Slots  Algorithms  Hard  
682  Baseball Game  Algorithms  Easy  
681  Next Closest Time  Algorithms  Medium  
680  Valid Palindrome II  Algorithms  Easy  
679  24 Game  Algorithms  Hard  
678  Valid Parenthesis String  Algorithms  Medium  
677  Map Sum Pairs  Algorithms  Medium  
676  Implement Magic Dictionary  Algorithms  Medium  
675  Cut Off Trees for Golf Event  Algorithms  Hard  
674  Longest Continuous Increasing Subsequence  Algorithms  Easy  
673  Number of Longest Increasing Subsequence  Algorithms  Medium  
672  Bulb Switcher II  Algorithms  Medium  
671  Second Minimum Node In a Binary Tree  Algorithms  Easy  
670  Maximum Swap  Algorithms  Medium  
669  Trim a Binary Search Tree  Algorithms  Easy  
668  Kth Smallest Number in Multiplication Table  Algorithms  Hard  
667  Beautiful Arrangement II  Algorithms  Medium  
666  Path Sum IV  Algorithms  Medium  
665  Nondecreasing Array  Algorithms  Easy  
664  Strange Printer  Algorithms  Hard  
663  Equal Tree Partition  Algorithms  Medium  
662  Maximum Width of Binary Tree  Algorithms  Medium  
661  Image Smoother  Algorithms  Easy  
660  Remove 9  Algorithms  Medium  
659  Split Array into Consecutive Subsequences  Algorithms  Medium  
658  Find K Closest Elements  Algorithms  Medium  
657  Judge Route Circle  Algorithms  Easy  
656  Coin Path  Algorithms  Hard  
655  Print Binary Tree  Algorithms  Medium  
654  Maximum Binary Tree  Algorithms  Medium  
653  Two Sum IV  Input is a BST  Algorithms  Easy  
652  Find Duplicate Subtrees  Algorithms  Medium  
651  4 Keys Keyboard  Algorithms  Medium  
650  2 Keys Keyboard  Algorithms  Medium  
649  Dota2 Senate  Algorithms  Medium  
648  Replace Words  Algorithms  Hard  
647  Palindromic Substrings  Algorithms  Medium  
646  Maximum Length of Pair Chain  Algorithms  Medium  
645  Set Mismatch  Algorithms  Easy  
644  Maximum Average Subarray II  Algorithms  Hard  
643  Maximum Average Subarray I  Algorithms  Easy  
642  Design Search Autocomplete System  Algorithms  Hard  
640  Solve the Equation  Algorithms  Medium  
639  Decode Ways II  Algorithms  Hard  
638  Shopping Offers  Algorithms  Medium  
637  Average of Levels in Binary Tree  Algorithms  Easy  
636  Exclusive Time of Functions  Algorithms  Medium  
635  Design Log Storage System  Algorithms  Medium  
634  Find the Derangement of An Array  Algorithms  Medium  
633  Sum of Square Numbers  Algorithms  Easy  
632  Smallest Range  Algorithms  Hard  
631  Design Excel Sum Formula  Algorithms  Hard  
630  Course Schedule III  Algorithms  Medium  
629  K Inverse Pairs Array  Algorithms  Medium  
628  Maximum Product of Three Numbers  Algorithms  Easy  
625  Minimum Factorization  Algorithms  Medium  
624  Maximum Distance in Arrays  Algorithms  Easy  
623  Add One Row to Tree  Algorithms  Medium  
621  Task Scheduler  Algorithms  Medium  
617  Merge Two Binary Trees  Algorithms  Easy  
616  Add Bold Tag in String  Algorithms  Medium  
611  Valid Triangle Number  Algorithms  Medium  
609  Find Duplicate File in System  Algorithms  Medium  
606  Construct String from Binary Tree  Algorithms  Easy  
605  Can Place Flowers  Algorithms  Easy  
604  Design Compressed String Iterator  Algorithms  Easy  
600  Nonnegative Integers without Consecutive Ones  Algorithms  Hard  
599  Minimum Index Sum of Two Lists  Algorithms  Easy  
598  Range Addition II  Algorithms  Easy  
594  Longest Harmonious Subsequence  Algorithms  Easy  
593  Valid Square  Algorithms  Medium  
592  Fraction Addition and Subtraction  Algorithms  Medium  
591  Tag Validator  Algorithms  Hard  
588  Design InMemory File System  Algorithms  Hard  
587  Erect the Fence  Algorithms  Hard  
583  Delete Operation for Two Strings  Algorithms  Medium  
582  Kill Process  Algorithms  Medium  
581  Shortest Unsorted Continuous Subarray  Algorithms  Easy  
580  Count Student Number in Departments  Database  Medium  
578  Get Highest Answer Rate Question  Database  Medium  
577  Employee Bonus  Database  Easy  
576  Out of Boundary Paths  Algorithms  Medium  
575  Distribute Candies  Algorithms  Easy  
573  Squirrel Simulation  Algorithms  Medium  
572  Subtree of Another Tree  Algorithms  Easy  
571  Find Median Given Frequency of Numbers  Database  Easy  
568  Maximum Vacation Days  Algorithms  Hard  
567  Permutation in String  Algorithms  Medium  
566  Reshape the Matrix  Algorithms  Easy  
565  Array Nesting  Algorithms  Easy  
564  Find the Closest Palindrome  Algorithms  Hard  
563  Binary Tree Tilt  Algorithms  Easy  
562  Longest Line of Consecutive One in Matrix  Algorithms  Medium  
561  Array Partition I  Algorithms  Easy  
560  Subarray Sum Equals K  Algorithms  Medium  
557  Reverse Words in a String III  Algorithms  Easy  
556  Next Greater Element III  Algorithms  Medium  
555  Split Assembled Strings  Algorithms  Medium  
554  Brick Wall  Algorithms  Medium  
553  Optimal Division  Algorithms  Medium  
552  Student Attendance Record II  Algorithms  Hard  
551  Student Attendance Record I  Algorithms  Easy  
549  Binary Tree Longest Consecutive Sequence II  Algorithms  Medium  
548  Split Array with Equal Sum  Algorithms  Medium  
547  Friend Circles  Algorithms  Medium  
546  Remove Boxes  Algorithms  Hard  
545  Boundary of Binary Tree  Algorithms  Medium  
544  Output Contest Matches  Algorithms  Medium  
543  Diameter of Binary Tree  Algorithms  Easy  
542  01 Matrix  Algorithms  Medium  
541  Reverse String II  Algorithms  Easy  
540  Single Element in a Sorted Array  Draft  Medium  
539  Minimum Time Difference  Algorithms  Medium  
538  Convert BST to Greater Tree  Algorithms  Easy  
537  Complex Number Multiplication  Algorithms  Medium  
536  Construct Binary Tree from String  Algorithms  Medium  
533  Lonely Pixel II  Algorithms  Medium  
532  Kdiff Pairs in an Array  Algorithms  Easy  
531  Lonely Pixel I  Algorithms  Medium  
530  Minimum Absolute Difference in BST  Algorithms  Easy  
529  Minesweeper  Algorithms  Medium  
527  Word Abbreviation  Algorithms  Hard  
526  Beautiful Arrangement  Algorithms  Medium  
525  Contiguous Array  Algorithms  Medium  
524  Longest Word in Dictionary through Deleting  Algorithms  Medium  
523  Continuous Subarray Sum  Algorithms  Medium  
522  Longest Uncommon Subsequence II  Algorithms  Medium  
521  Longest Uncommon Subsequence I  Algorithms  Easy  
520  Detect Capital  Algorithms  Easy  
518  Coin Change 2  Draft  Medium  
517  Super Washing Machines  Algorithms  Hard  
516  Longest Palindromic Subsequence  Algorithms  Medium  
515  Find Largest Element in Each Row  Algorithms  Medium  
514  Freedom Trail  Algorithms  Hard  
513  Find Left Most Element  Algorithms  Medium  
508  Most Frequent Subtree Sum  Algorithms  Medium  
507  Perfect Number  Algorithms  Easy  
506  Relative Ranks  Algorithms  Easy  
504  Base 7  Algorithms  Easy  
503  Next Greater Element II  Algorithms  Medium  
502  IPO  Algorithms  Hard  
501  Find Mode in Binary Tree  Algorithms  Easy  
500  Keyboard Row  Algorithms  Easy  
499  The Maze II  Algorithms  Hard  
498  Diagonal Traverse  Algorithms  Hard  
496  Next Greater Element I  Algorithms  Easy  
495  Teemo Attacking  Algorithms  Medium  
494  Target sum  Algorithms  Medium  
493  Reverse Pairs  Algorithms  Hard  
492  Construct the rectangle  Algorithms  Easy  
491  Increasing Subsequences  Algorithms  Medium  
488  Zuma Game  Algorithms  Hard  
487  Max Consecutive Ones II  Algorithms  Medium  
486  Predict the Winner  Algorithms  Medium  
485  Max Consecutive Ones  Algorithms  Easy  
484  Find Permutation  Algorithms  Medium  
483  Smallest Good Base  Algorithms  Hard  
482  License Key Formatting  Algorithms  Medium  
481  Magical String  Algorithms  Medium  
480  Sliding Window Median  Algorithms  Hard  
479  Largest Palindrome Product  Draft  Easy  
477  Total Hamming Distance  Algorithms  Medium  
476  Number Complement  Algorithms  Easy  
475  Heaters  Algorithms  Easy  
474  Ones and Zeroes  Algorithms  Medium  
473  Matchsticks to Square  Algorithms  Medium  
471  Encode String with Shortest Length  Algorithms  Hard  
469  Convex Polygon  Algorithms  Medium  
468  Validate IP Address  Algorithms  Medium  
467  Unique Substrings in Wraparound String  Algorithms  Medium  
466  Count The Repetitions  Algorithms  Hard  
465  Optimal Account Balancing  Algorithms  Hard  
464  Can I Win  Algorithms  Medium  
463  Island Perimeter  Algorithms  Easy  
462  Minimum Moves to Equal Array Elements II  Algorithms  Medium  
461  Hamming Distance  Algorithms  Easy  
460  LFU Cache  Draft  Hard  
459  Repeated Substring Pattern  Algorithms  Easy  
458  Poor Pigs  Draft  Easy  
457  Circular Array Loop  Draft  Medium  
456  132 Pattern  Algorithms  Medium  
455  Assign Cookies  Algorithms  Easy  
454  4Sum II  Algorithms  Medium  
453  Minimum Moves to Equal Array Elements  Algorithms  Easy  
452  Minimum Number of Arrows to Burst Balloons  Algorithms  Medium  
451  Sort Characters By Frequency  Draft  Medium  
450  Delete Node in a BST  Draft  Medium  
449  Serialize and Deserialize BST  Draft  Medium  
448  Find All Numbers Disappeared in an Array  Draft  Medium  
447  Number of Boomerangs  Algorithms  Easy  
446  Arithmetic Slices II  Subsequence  Algorithms  Hard  
445  Add Two Numbers II  Draft  Medium  
444  Sequence Reconstruction  Algorithms  Medium  
442  Find All Duplicates in an Array  Draft  Medium  
441  Arranging Coins  Algorithms  Easy  
440  Kth Smallest in Lexicographical Order  Algorithms  Hard  
439  Ternary Expression Parser  Algorithms  Medium  
438  Find All Anagrams in a String  Algorithms  Easy  
437  Path Sum III  Algorithms  Easy  
436  Find Right Interval  Algorithms  Medium  
435  Nonoverlapping Intervals  Algorithms  Medium  
434  Number of Segments in a String  Algorithms  Easy  
433  Minimum Genetic Mutation  Draft  Medium  
432  All O`one Data Structure  Draft  Hard  
425  Word Squares  Algorithms  Hard  
424  Longest Repeating Character Replacement  Algorithms  Medium  
423  Reconstruct Original Digits from English  Algorithms  Easy  
422  Valid Word Square  Algorithms  Easy  
421  Maximum XOR of Two Numbers in an Array  Algorithms  Medium  
420  Strong Password Checker  Algorithms  Hard  
419  Battleships in a board  Algorithms  Medium  
418  Sentence Screen Fitting  Algorithms  Hard  
417  Pacific Atlantic Water Flow  Algorithms  Medium  
416  Partition Equal Subset Sum  Algorithms  Medium  
415  Add Strings  Algorithms  Easy  
414  Third Maximum Number  Algorithms  Easy  
413  Arithmetic Slices  Algorithms  Easy  
412  Fizz Buzz  Algorithms  Easy  
411  Minimum Unique Word Abbreviation  Algorithms  Medium  
410  Split Array Largest Sum  Algorithms  Medium  
409  Longest Palindrome  Algorithms  Easy  
408  Valid Word Abbreviation  Algorithms  Easy  
407  Trapping Rain Water II  Algorithms  Hard  
406  Queue Reconstruction by Height  Algorithms  Medium  
405  Convert a Number to Hexadecimal  Algorithms  Easy  
404  Sum of Left Leaves  Algorithms  Easy  
403  Frog Jump  Algorithms  Hard  
402  Remove K Digits  Algorithms  Medium  
401  Binary Watch  Algorithms  Easy  
400  Nth Digit  Algorithms  Easy  
399  Evaluate Division  Algorithms  Medium  
398  Random Pick Index  Algorithms  Medium  
397  Integer Replacement  Algorithms  Easy  
396  Rotate Function  Algorithms  Easy  
395  Longest Substring with At Least K Repeating Characters  Algorithms  Medium  
394  Decode String  Algorithms  Medium  
393  UTF8 Validation  Algorithms  Medium  
392  Is Subsequence  Algorithms  Medium  
391  Perfect Rectangle  Algorithms  Hard  
390  Elimination Game  Algorithms  Medium  
389  Find the Difference  Algorithms  Easy  
388  Longest Absolute File Path  Algorithms  Medium  
387  First Unique Character in a String  Algorithms  Easy  
386  Lexicographical Numbers  Algorithms  Medium  
385  Mini Parser  Algorithms  Medium  
384  Shuffle an Array  Algorithms  Easy  
383  Ransom Note  Algorithms  Easy  
382  Linked List Random Node  Algorithms  Medium  
381  Insert Delete GetRandom O(1)  Duplicates allowed  Algorithms  Medium  
380  Insert Delete GetRandom O(1)  Algorithms  Medium  
378  Kth Smallest Element in a Sorted Matrix  Algorithms  Medium  
377  Combination Sum IV  Algorithms  Medium  
376  Wiggle Subsequence  Algorithms  Medium  
375  Guess Number Higher or Lower II  Algorithms  Medium  
374  Guess Number Higher or Lower  Algorithms  Easy  
373  Find K Pairs with Smallest Sums  Algorithms  Medium  
372  Super Pow  Algorithms  Medium  
371  Sum of Two Integers  Algorithms  Easy  
368  Largest Divisible Subset  Algorithms  Medium  
367  Valid Perfect Square  Algorithms  Medium  
365  Water and Jug Problem  Algorithms  Medium  
363  Max Sum of Rectangle No Larger Than K  Algorithms  Medium  
357  Count Numbers with Unique Digits  Algorithms  Medium  
355  Design Twitter designtwitter  Algorithms  Hard  
354  Russian Doll Envelopes  Algorithms  Hard  
352  Data Stream as Disjoint Intervals  Algorithms  Hard  
350  Intersection of Two Arrays II  Algorithms  Easy  
349  Intersection of Two Arrays  Algorithms  Easy  
347  Top K Frequent Elements  Algorithms  Medium  
345  Reverse Vowels of a String  Algorithms  Easy  
344  Reverse String  Algorithms  Easy  
343  Integer Break  Algorithms  Medium  
342  Power of Four  Algorithms  Easy  
341  Flatten Nested List Iterator  Algorithms  Medium  
338  Counting Bits  Algorithms  Medium  
337  House Robber III  Algorithms  Medium  
336  Palindrome Pairs  Algorithms  Hard  
335  Self Crossing  Algorithms  Medium  
334  Increasing Triplet Subsequence  Algorithms  Medium  
332  Reconstruct Itinerary  Algorithms  Hard  
331  Verify Preorder Serialization of a Binary Tree  Algorithms  Medium  
330  Patching Array  Algorithms  Hard  
329  Longest Increasing Path in a Matrix  Algorithms  Medium  
328  Odd Even Linked List  Algorithms  Easy  
327  Count of Range Sum  Algorithms  Hard  
326  Power of Three  Algorithms  Easy  
324  Wiggle Sort II  Algorithms  Medium  
322  Coin Change  Algorithms  Medium  
321  Create Maximum Number  Algorithms  Hard  
319  Bulb Switcher  Algorithms  Medium  
318  Maximum Product of Word Lengths  Algorithms  Medium  
316  Remove Duplicate Letters  Algorithms  Medium  
315  Count of Smaller Numbers After Self  Algorithms  Hard  
313  Super Ugly Number  Algorithms  Medium  
312  Burst Balloons  Algorithms  Medium  
310  Minimum Height Trees  Algorithms  Medium  
309  Best Time to Buy and Sell Stock with Cooldown  Algorithms  Medium  
307  Range Sum Query  Mutable  Algorithms  Medium  
306  Additive Number  Algorithms  Medium  
304  Range Sum Query 2D  Immutable  Algorithms  Medium  
303  Range Sum Query  Immutable  Algorithms  Easy  
301  Remove Invalid Parentheses  Algorithms  Medium  
300  Longest Increasing Subsequence  Algorithms  Medium  
299  Bulls and Cows  Algorithms  Easy  
297  Serialize and Deserialize Binary Tree  Algorithms  Medium  
295  Find Median from Data Stream  Algorithms  Hard  
292  Nim Game  Algorithms  Easy  
290  Word Pattern  Algorithms  Easy  
289  Game of Life  Algorithms  Medium  
287  Find the Duplicate Number  Algorithms  Hard  
284  Peeking Iterator peekingiterator  Algorithms  Medium  
283  Move Zeroes  Algorithms  Easy  
282  Expression Add Operators  Algorithms  Hard  
279  Perfect Squares  Algorithms  Medium  
278  First Bad Version  Algorithms  Easy  
275  HIndex II  Algorithms  Medium  
274  HIndex  Algorithms  Medium  
273  Integer to English Words  Algorithms  Medium  
268  Missing Number  Algorithms  Medium  
264  Ugly Number II  Algorithms  Medium  
263  Ugly Number  Algorithms  Easy  
262  Trips and Users  Database  Hard  
260  Single Number III  Algorithms  Medium  
258  Add Digits  Algorithms  Easy  
257  Binary Tree Paths  Algorithms  Easy  
242  Valid Anagram  Algorithms  Easy  
241  Different Ways to Add Parentheses  Algorithms  Medium  
240  Search a 2D Matrix II  Algorithms  Medium  
239  Sliding Window Maximum  Algorithms  Hard  
238  Product of Array Except Self  Algorithms  Medium  
237  Delete Node in a Linked List  Algorithms  Easy  
236  Lowest Common Ancestor of a Binary Tree  Algorithms  Medium  
235  Lowest Common Ancestor of a Binary Search Tree  Algorithms  Easy  
234  Palindrome Linked List  Algorithms  Easy  
233  Number of Digit One  Algorithms  Medium  
232  Implement Queue using Stacks  Algorithms  Easy  
231  Power of Two  Algorithms  Easy  
230  Kth Smallest Element in a BST  Algorithms  Medium  
229  Majority Element II  Algorithms  Medium  
228  Summary Ranges  Algorithms  Easy  
227  Basic Calculator II  Algorithms  Medium  
226  Invert Binary Tree  Algorithms  Easy  
225  Implement Stack using Queues  Algorithms  Easy  
224  Basic Calculator  Algorithms  Medium  
223  Rectangle Area  Algorithms  Easy  
222  Count Complete Tree Nodes  Algorithms  Medium  
221  Maximal Square  Algorithms  Medium  
220  Contains Duplicate III  Algorithms  Medium  
219  Contains Duplicate II  Algorithms  Easy  
218  The Skyline Problem  Algorithms  Hard  
217  Contains Duplicate  Algorithms  Easy  
216  Combination Sum III  Algorithms  Medium  
215  Kth Largest Element in an Array  Algorithms  Medium  
214  Shortest Palindrome  Algorithms  Hard  
213  House Robber II  Algorithms  Medium  
212  Word Search II  Algorithms  Hard  
211  Add and Search Word  Data structure design  Algorithms  Medium  
210  Course Schedule II  Algorithms  Medium  
209  Minimum Size Subarray Sum  Algorithms  Medium  
208  Implement Trie (Prefix Tree)  Algorithms  Medium  
207  Course Schedule  Algorithms  Medium  
206  Reverse Linked List  Algorithms  Easy  
205  Isomorphic Strings  Algorithms  Easy  
204  Count Primes  Algorithms  Easy  
203  Remove Linked List Elements  Algorithms  Easy  
202  Happy Number  Algorithms  Easy  
201  Bitwise AND of Numbers Range  Algorithms  Medium  
200  Number of Islands  Algorithms  Medium  
199  Binary Tree Right Side View  Algorithms  Medium  
198  House Robber  Algorithms  Easy  
197  Rising Temperature  Database  Easy  
196  Delete Duplicate Emails  Database  Easy  
195  Tenth Line  Shell  Easy  
194  Transpose File  Shell  Medium  
193  Valid Phone Numbers  Shell  Easy  
192  Word Frequency  Shell  Medium  
191  Number of 1 Bits  Algorithms  Easy  
190  Reverse Bits  Algorithms  Easy  
189  Rotate Array  Algorithms  Easy  
188  Best Time to Buy and Sell Stock IV  Algorithms  Hard  
187  Repeated DNA Sequences  Algorithms  Medium  
185  Department Top Three Salaries  Database  Hard  
184  Department Highest Salary  Database  Medium  
183  Customers Who Never Order  Database  Easy  
182  Duplicate Emails  Database  Easy  
181  Employees Earning More Than Their Managers  Database  Easy  
180  Consecutive Numbers  Database  Medium  
179  Largest Number  Algorithms  Medium  
178  Rank Scores  Database  Medium  
177  Nth Highest Salary  Database  Medium  
176  Second Highest Salary  Database  Easy  
175  Combine Two Tables  Database  Easy  
174  Dungeon Game  Algorithms  Hard  
173  Binary Search Tree Iterator  Algorithms  Medium  
172  Factorial Trailing Zeroes  Algorithms  Easy  
171  Excel Sheet Column Number  Algorithms  Easy  
169  Majority Element  Algorithms  Easy  
168  Excel Sheet Column Title  Algorithms  Easy  
166  Fraction to Recurring Decimal  Algorithms  Medium  
165  Compare Version Numbers  Algorithms  Easy  
164  Maximum Gap  Algorithms  Hard  
162  Find Peak Element  Algorithms  Medium  
160  Intersection of Two Linked Lists  Algorithms  Easy  
155  Min Stack  Algorithms  Easy  
154  Find Minimum in Rotated Sorted Array II  Algorithms  Hard  
153  Find Minimum in Rotated Sorted Array  Algorithms  Medium  
152  Maximum Product Subarray  Algorithms  Medium  
151  Reverse Words in a String  Algorithms  Medium  
150  Evaluate Reverse Polish Notation  Algorithms  Medium  
149  Max Points on a Line  Algorithms  Easy  
148  Sort List  Algorithms  Medium  
147  Insertion Sort List  Algorithms  Medium  
146  LRU Cache  Algorithms  Hard  
145  Binary Tree Postorder Traversal  Algorithms  Hard  
144  Binary Tree Preorder Traversal  Algorithms  Medium  
143  Reorder List  Algorithms  Medium  
142  Linked List Cycle II  Algorithms  Medium  
141  Linked List Cycle  Algorithms  Medium  
140  Word Break II  Algorithms  Hard  
139  Word Break  Algorithms  Medium  
138  Copy List with Random Pointer  Algorithms  Hard  
136  Single Number  Algorithms  Medium  
135  Candy  Algorithms  Hard  
134  Gas Station  Algorithms  Medium  
133  Clone Graph  Algorithms  Medium  
129  Sum Root to Leaf Numbers  Algorithms  Medium  
127  Word Ladder  Algorithms  Medium  
124  Binary Tree Maximum Path Sum  Algorithms  Hard  
122  Best Time to Buy and Sell Stock II  Algorithms  Medium  
114  Flatten Binary Tree to Linked List  Algorithms  Medium  
111  Minimum Depth of Binary Tree  Algorithms  Easy  
100  Same Tree  Algorithms  Easy  
94  Binary Tree Inorder Traversal  Algorithms  Medium  
92  Reverse Linked List II  Algorithms  Medium  
79  Word Search  Algorithms  Medium  
70  Climbing Stairs  Algorithms  Easy  
69  Sqrt(x)  Algorithms  Medium  
62  Unique Paths  Algorithms  Medium  
49  Anagrams  Algorithms  Medium  
46  Permutations  Algorithms  Medium  
41  First Missing Positive  Algorithms  Hard  
31  Next Permutation  Algorithms  Medium  
30  Substring with Concatenation of All Words  Algorithms  Hard  
8  String to Integer (atoi)  Algorithms  Easy  
6  ZigZag Conversion  Algorithms  Easy  
4  Median of Two Sorted Arrays  Algorithms  Hard  
3  Longest Substring Without Repeating Characters  Algorithms  Medium  
2  Add Two Numbers  Algorithms  Medium  
1  Two Sum  Algorithms  Medium 