/LeetCode_solutions

203 efficient solutions to LeetCode problems


203 efficient solutions to LeetCode problems

# Question Solution Difficulty
1 Two Sum Solution Easy
2 Add Two Numbers Solution Medium
4 Median of Two Sorted Arrays Solution Hard
5 Longest Palindromic Substring Solution Medium
7 Reverse Integer Solution Easy
9 Palindrome Number Solution Easy
13 Roman to Integer Solution Easy
14 Longest Common Prefix Solution Easy
15 3sum Solution Medium
16 3sum Closest Solution Medium
17 Letter Combinations of a Phone Number Solution Medium
19 Remove Nth Node From End of List Solution Medium
20 Valid Parentheses Solution Easy
21 Merge Two Sorted Lists Solution Easy
22 Generate Parentheses Solution Medium
23 Merge k Sorted Lists Solution Hard
26 Remove Duplicates from Sorted Array Solution Easy
27 Remove Element Solution Easy
28 Implement strStr() Solution Easy
33 Search in Rotated Sorted Array Solution Medium
34 Find First and Last Position of Element in Sorted Array Solution Medium
35 Search Insert Position Solution Easy
38 Count and Say Solution Easy
42 Trapping Rain Water Solution Hard
46 Permutations Solution Medium
47 Permutations II Solution Medium
48 Rotate Image Solution Medium
49 Group Anagrams Solution Medium
51 N-Queens Solution Hard
52 N-Queens II Solution Hard
53 Maximum Subarray Solution Easy
55 Jump Game Solution Medium
58 Length of Last Word Solution Easy
62 Unique Paths Solution Medium
63 Unique Paths II Solution Medium
66 Plus One Solution Easy
67 Add Binary Solution Easy
69 Sqrt(x) Solution Easy
70 Climbing Stairs Solution Easy
73 Set Matrix Zeroes Solution Medium
78 Subsets Solution Medium
80 Remove Duplicates from Sorted Array II Solution Medium
81 Search in Rotated Sorted Array II Solution Medium
82 Remove Duplicates from Sorted List II Solution Medium
83 Remove Duplicates from Sorted List Solution Easy
88 Merge Sorted Array Solution Easy
90 Subsets II Solution Medium
92 Reverse Linked List II Solution Medium
94 Binary Tree Inorder Traversal Solution Medium
98 Validate Binary Search Tree Solution Medium
100 Same Tree Solution Easy
101 Symmetric Tree Solution Easy
102 Binary Tree Level Order Traversal Solution Medium
104 Maximum Depth of Binary Tree Solution Easy
107 Binary Tree Level Order Traversal II Solution Easy
108 Convert Sorted Array to Binary Search Tree Solution Easy
110 Balanced Binary Tree Solution Easy
111 Minimum Depth of Binary Tree Solution Easy
118 Pascal's Triangle Solution Easy
119 Pascal's Triangle II Solution Easy
121 Best Time to Buy and Sell Stock Solution Easy
122 Best Time to Buy and Sell Stock II Solution Easy
125 Valid Palindrome Solution Easy
127 Word Ladder Solution Medium
136 Single Number Solution Easy
139 Word Break Solution Medium
141 Linked List Cycle Solution Easy
142 Linked List Cycle II Solution Medium
143 Reorder List Solution Medium
144 Binary Tree Preorder Traversal Solution Medium
145 Binary Tree Postorder Traversal Solution Hard
146 LRU Cache Solution Medium
148 Sort List Solution Medium
149 Max Points on a Line Solution Hard
151 Reverse Words in a String Solution Medium
155 Min Stack Solution Easy
160 Intersection of Two linked Lists Solution Easy
162 Find Peak Element Solution Medium
167 Two Sum II - Input array is sorted Solution Easy
168 Excel Sheet Column Title Solution Easy
169 Majority Element Solution Easy
171 Excel Sheet Column Number Solution Easy
172 Factorial Trailing Zeroes Solution Easy
175 Combine Two Tables Solution Easy
176 Second Highest Salary Solution Easy
177 Nth Highest Salary Solution Medium
178 Rank Scores Solution Medium
180 Consecutive Numbers Solution Medium
181 Employees Earning More Than Their Managers Solution Easy
182 Duplicate Emails Solution Easy
183 Customers Who Never Order Solution Easy
184 Department Highest Salary Solution Medium
185 Department Top Three Salaries Solution Hard
189 Rotate Array Solution Easy
190 Reverse Bits Solution Easy
191 Number of 1 Bits Solution Easy
196 Delete Duplicate Emails Solution Easy
197 Rising Temperature Solution Easy
198 House Robber Solution Easy
200 Number of Islands Solution Medium
202 Happy Number Solution Easy
203 Remove Linked List Elements Solution Easy
204 Count Primes Solution Easy
206 Reverse Linked List Solution Easy
207 Course Schedule Solution Medium
208 Implement Trie (Prefix Tree) Solution Medium
210 Course Schedule II Solution Medium
217 Contains Duplicate Solution Easy
226 Invert Binary Tree Solution Easy
231 Power of Two Solution Easy
232 Implement Queue using Stacks Solution Easy
234 Palindrome Linked List Solution Easy
235 Lowest Common Ancestor of a Binary Search Tree Solution Easy
236 Lowest Common Ancestor of a Binary Tree Solution Medium
237 Delete Node in a Linked List Solution Easy
238 Product of Array Except Self Solution Medium
239 Sliding Window Maximum Solution Hard
240 Search a 2D Matrix II Solution Medium
242 Valid Anagram Solution Easy
262 Trips and Users Solution Hard
263 Ugly Number Solution Easy
264 Ugly Number II Solution Medium
268 Missing Number Solution Easy
273 Integer to English Words Solution Hard
278 First Bad Version Solution Easy
283 Move Zeroes Solution Easy
290 Word Pattern Solution Easy
292 Nim Game Solution Easy
295 Find Median from Data Stream Solution Hard
300 Longest Increasing Subsequence Solution Medium
303 Range Sum Query - Immutable Solution Easy
309 Best Time to Buy and Sell Stock with Cooldown Solution Medium
326 Power of Three Solution Easy
328 Odd Even Linked List Solution Medium
342 Power of Four Solution Easy
344 Reverse String Solution Easy
347 Top K Frequent Elements Solution Medium
349 Intersection of Two Arrays Solution Easy
350 Intersection of Two Arrays II Solution Easy
354 Russian Doll Envelopes Solution Hard
367 Valid Perfect Square Solution Easy
371 Sum of Two Integers Solution Easy
380 Insert Delete GetRandom O(1) Solution Medium
381 Insert Delete GetRandom O(1) - Duplicates allowed Solution Hard
383 Ransom Note Solution Easy
384 Shuffle an Array Solution Medium
387 First Unique Character in a String Solution Easy
389 Find the Difference Solution Easy
412 Fizz Buzz Solution Easy
414 Third Maximum Number Solution Easy
429 N-ary Tree Level Order Traversal Solution Easy
437 Path Sum III Solution Easy
442 Find All Duplicates in an Array Solution Medium
443 String Compression Solution Easy
445 Add Two Numbers II Solution Medium
448 Find All Numbers Disappeared in an Array Solution Easy
454 4Sum II Solution Medium
461 Hamming Distance Solution Easy
470 Implement Rand10() Using Rand7() Solution Medium
477 Total Hamming Distance Solution Medium
480 Sliding Window Median Solution Hard
500 Keyboard Row Solution Easy
509 Fibonacci Number Solution Easy
516 Longest Palindromic Subsequence Solution Medium
518 Coin Change 2 Solution Medium
520 Detect Capital Solution Easy
525 Contiguous Array Solution Medium
543 Diameter of Binary Tree Solution Easy
559 Maximum Depth of N-ary Tree Solution Easy
560 Subarray Sum Equals K Solution Medium
572 Subtree of Another Tree Solution Easy
581 Shortest Unsorted Continuous Subarray Solution Easy
589 N-ary Tree Preorder Traversal Solution Easy
590 N-ary Tree Postorder Traversal Solution Easy
595 Big Countries Solution Easy
596 Classes More Than 5 Students Solution Easy
601 Human Traffic of Stadium Solution Hard
617 Merge Two Binary Trees Solution Easy
620 Not Boring Movies Solution Easy
626 Exchange Seats Solution Medium
627 Swap Salary Solution Easy
692 Top K Frequent Words Solution Medium
695 Max Area of Island Solution Medium
703 Kth Largest Element in a Stream Solution Easy
704 Binary Search Solution Easy
706 Design HashMap Solution Easy
707 Design Linked List Solution Easy
709 To Lower Case Solution Easy
733 Flood Fill Solution Easy
771 Jewels and Stones Solution Easy
895 Maximum Frequency Stack Solution Hard
912 Sort an Array Solution Medium
976 Largest Perimeter Triangle Solution Easy
1010 Pairs of Songs With Total Durations Divisible by 60 Solution Easy
1092 Shortest Common Supersequence Solution Hard
1114 Print in Order Solution Easy
1115 Print FooBar Alternately Solution Medium
1116 Print Zero Even Odd Solution Medium
1117 Building H2O Solution Medium
1139 Largest 1-Bordered Square Solution Medium
1179 Reformat Department Table Solution Easy
1195 Fizz Buzz Multithreaded Solution Medium
1207 Unique Number of Occurrences Solution Easy