LeetCode Top 100 Liked Questions === The user's favorite 100 problems are very classic. If you are a newbie, this is the best way to get started with leetcode. Language: Java *If there was something wrong, you can new a issue. Welcome to improve this project with me.* --- 用户最喜欢的100道题都是很经典的问题，是新手入门 leetcode 的最好方式。**每道题在代码头部都添加了我的解题思路和想法，希望对你有用**。 语言: Java *相关问题可以直接提交一个issue，欢迎和我一起完善这个项目* --- ### Top 100 Liked Questions | \# | Problems | Difficulty | Solution | |----|----------|-----------|------| | 001 | [Two_Sum](https://leetcode.com/problems/two-sum/) | Easy | [Java](./code/lc1.java) | 002 | [Add Two Numbers](https://leetcode.com/problems/add-two-numbers/) |Medium| [Java](./code/lc2.java) | 003 | [Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/) | Medium | [Java](./code/lc3.java) | 004 | [Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays) | Hard | [Java](./code/lc4.java) | 005 | [Longest Palindromic Substring](https://leetcode.com/problems/longest-palindromic-substring/) |Medium|[Java](./code/lc5.java) | 010 | [Regular Expression Matching](https://leetcode.com/problems/regular-expression-matching/) | Hard | [Java](./code/lc10.java) | 011 | [Container With Most Water](https://leetcode.com/problems/container-with-most-water/) |Medium| [Java](./code/lc11.java) | 015 | [3Sum](https://leetcode.com/problems/3sum/) |Medium| [Java](./code/lc15.java) | 017 | [Letter Combinations of a Phone Number](https://leetcode.com/problems/letter-combinations-of-a-phone-number/) |Medium| [Java](./code/lc17.java) | 019 | [Remove Nth Node From End of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list/) | Easy | [Java](./code/lc19.java) | 020 | [Valid Parentheses](https://leetcode.com/problems/valid-parentheses/) | Easy | [Java](./code/lc20.java) | 021 | [Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/) | Easy | [Java](./code/lc21.java) | 022 | [Generate Parentheses](https://leetcode.com/problems/generate-parentheses/) |Medium| [Java](./code/lc22.java) | 023 | [Merge k Sorted Lists](https://leetcode.com/problems/merge-k-sorted-lists/) | Hard | [Java](./code/lc23.java) | 032 | [Longest Valid Parentheses](https://leetcode.com/problems/longest-valid-parentheses/) | Hard | [Java](./code/lc32.java) | 033 | [Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array/) |Medium| [Java](./code/lc33.java) | 034 | [Search for a Range](https://leetcode.com/problems/search-for-a-range/) |Medium| [Java](./code/lc34.java) | 035 | [Search Insert Position](https://leetcode.com/problems/search-insert-position/) |Medium| [Java](./code/lc35.java) | 039 | [Combination Sum](https://leetcode.com/problems/combination-sum/) |Medium| [Java](./code/lc39.java) | 042 | [Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water/) | Hard | [Java](./code/lc42.java) | 046 | [Permutations](https://leetcode.com/problems/permutations/) |Medium| [Java](./code/lc46.java) | 048 | [Rotate Image](https://leetcode.com/problems/rotate-image/) |Medium| [Java](./code/lc48.java) | 049 | [Group Anagrams](https://leetcode.com/problems/anagrams/)|Medium| [Java](./code/lc49.java) | 053 | [Maximum Subarray](https://leetcode.com/problems/maximum-subarray/) |Medium| [Java](./code/lc53.java) | 055 | [Jump Game](https://leetcode.com/problems/jump-game/) |Medium| [Java](./code/lc55.java) | 056 | [Merge Intervals](https://leetcode.com/problems/merge-intervals/) |Medium| [Java](./code/lc56.java) | 062 | [Unique Paths](https://leetcode.com/problems/unique-paths/) |Medium| [Java](./code/lc62.java) | 064 | [Minimum Path Sum](https://leetcode.com/problems/minimum-path-sum/) |Medium| [Java](./code/lc64.java) | 070 | [Climbing Stairs](https://leetcode.com/problems/climbing-stairs/) | Easy | [Java](./code/lc70.java) | 072 | [Edit Distance](https://leetcode.com/problems/edit-distance/) | Hard | [Java](./code/lc72.java) | 075 | [Sort Colors](https://leetcode.com/problems/sort-colors/)|Medium| [Java](./code/lc75.java) | 076 | [Minimum Window Substring](https://leetcode.com/problems/minimum-window-substring) | Hard| [Java](./code/lc76.java) | 078 | [Subsets](https://leetcode.com/problems/subsets/) |Medium| [Java](./code/lc78.java) | 079 | [Word Search](https://leetcode.com/problems/word-search/)|Medium| [Java](./code/lc79.java) | 084 | [Largest Rectangle in Histogram](https://leetcode.com/problems/largest-rectangle-in-histogram) | Hard | [Java](./code/lc84.java) | 085 | [Maximal Rectangle](https://leetcode.com/problems/maximal-rectangle) | Hard |[Java](./code/lc85.java) | 094 | [Binary Tree Inorder Traversal](https://leetcode.com/problems/binary-tree-inorder-traversal/) |Medium| [Java](./code/lc94.java) | 096 | [Unique Binary Search Trees](https://leetcode.com/problems/unique-binary-search-trees/) |Medium| [Java](./code/lc96.java) | 098 | [Validate Binary Search Tree](https://leetcode.com/problems/validate-binary-search-tree/) |Medium| [Java](./code/lc98.java) | 100 | [Same Tree](https://leetcode.com/problems/same-tree/) | Easy | [Java](./code/lc100.java) | 101 | [Symmetric Tree](https://leetcode.com/problems/symmetric-tree/) | Easy | [Java](./code/lc101.java) | 102 | [Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/) | Easy | [Java](./code/lc102.java) | 104 | [Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree/) | Easy | [Java](./code/lc104.java) | 105 | [Construct Binary Tree from Preorder and Inorder Traversal](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/) |Medium| [Java](./code/lc105.java) | 114 | [Flatten Binary Tree to Linked List](https://leetcode.com/problems/flatten-binary-tree-to-linked-list/) |Medium| [Java](./code/lc114.java) | 121 | [Best Time to Buy and Sell Stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/) | Easy | [Java](./code/lc121.java) | 124 | [Binary Tree Maximum Path Sum](https://leetcode.com/problems/binary-tree-maximum-path-sum/) | Hard | [Java](./code/lc124.java) | 128 | [Longest Consecutive Sequence](https://leetcode.com/problems/longest-consecutive-sequence/) | Hard | [Java](./code/lc128.java) | 136 | [Single Number](https://leetcode.com/problems/single-number) | Easy | [Java](./code/lc136.java) | 139 | [Word Break](https://leetcode.com/problems/word-break/) |Medium| [Java](./code/lc139.java) | 141 | [Linked List Cycle](https://leetcode.com/problems/linked-list-cycle/) | Easy | [Java](./code/lc141.java) | 142 | [Linked List Cycle II](https://leetcode.com/problems/linked-list-cycle-ii/) |Medium| [Java](./code/lc142.java) | 146 | [LRU Cache](https://leetcode.com/problems/lru-cache/) | Hard | [Java](./code/lc146.java) | 148 | [Sort List](https://leetcode.com/problems/sort-list/) |Medium| [Java](./code/lc148.java) | 152 | [Maximum Product Subarray](https://leetcode.com/problems/maximum-product-subarray/) |Medium| [Java](./code/lc152.java) | 155 | [Min Stack](https://leetcode.com/problems/min-stack/) | Easy | [Java](./code/lc155.java) | 160 | [Intersection of Two Linked Lists](https://leetcode.com/problems/intersection-of-two-linked-lists/) | Easy | [Java](./code/lc160.java) | 169 | [Majority Element](https://leetcode.com/problems/majority-element/) | Easy | [Java](./code/lc169.java) | 198 | [House Robber](https://leetcode.com/problems/house-robber/) | Easy | [Java](./code/lc198.java) | 200 | [Number of Islands](https://leetcode.com/problems/number-of-islands/) |Medium| [Java](./code/lc200.java) | 206 | [Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/) | Easy |[Java](./code/lc206.java) | 207 | [Course Schedule](https://leetcode.com/problems/course-schedule/) |Medium|[Java](./code/lc207.java) | 208 | [Implement Trie (Prefix Tree)](https://leetcode.com/problems/implement-trie-prefix-tree/) |Medium| [Java](./code/lc208.java) | 215 | [Kth Largest Element in an Array](https://leetcode.com/problems/kth-largest-element-in-an-array/) |Medium| [Java](./code/lc215.java) | 221 | [Maximal Square](https://leetcode.com/problems/maximal-square/) |Medium| [Java](./code/lc221.java) | 226 | [Invert Binary Tree](https://leetcode.com/problems/invert-binary-tree/) | Easy | [Java](./code/lc226.java) | 234 | [Palindrome Linked List](https://leetcode.com/problems/palindrome-linked-list/) | Easy | [Java](./code/lc234.java) | 236 | [Lowest Common Ancestor of a Binary Tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/) |Medium| [Java](./code/lc236.java) | 238 | [Product of Array Except Self](https://leetcode.com/problems/product-of-array-except-self/) |Medium| [Java](./code/lc238.java) | 239 | [Sliding Window Maximum](https://leetcode.com/problems/sliding-window-maximum/) | Hard | [Java](./code/lc239.java) | 240 | [Search a 2D Matrix II](https://leetcode.com/problems/search-a-2d-matrix-ii/) |Medium| [Java](./code/lc240.java) | 279 | [Perfect Squares](https://leetcode.com/problems/perfect-squares/) |Medium| [Java](./code/lc279.java) | 283 | [Move Zeroes](https://leetcode.com/problems/move-zeroes/)| Easy | [Java](./code/lc283.java) | 287 | [Find the Duplicate Number](https://leetcode.com/problems/find-the-duplicate-number/) | Hard | [Java](./code/lc287.java) | 297 | [Serialize and Deserialize Binary Tree](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/) | Hard | [Java](./code/lc297.java) | 300 | [Longest Increasing Subsequence](https://leetcode.com/problems/longest-increasing-subsequence/) |Medium| [Java](./code/lc300.java) | 301 | [Remove Invalid Parentheses](https://leetcode.com/problems/remove-invalid-parentheses/) |Hard| [Java](./code/lc301.java) | 309 | [Best Time to Buy and Sell Stock with Cooldown](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/) |Medium| [Java](./code/lc309.java) | 312 | [Burst Balloons](https://leetcode.com/problems/burst-balloons/) | Hard | [Java](./code/lc312.java) | 322 | [Coin Change](https://leetcode.com/problems/coin-change/)|Medium| [Java](./code/lc322.java) | 337 | [House Robber III](https://leetcode.com/problems/house-robber-iii/) |Medium| [Java](./code/lc337.java) | 338 | [Counting Bits](https://leetcode.com/problems/counting-bits/) |Medium| [Java](./code/lc338.java) | 347 | [Top K Frequent Elements](https://leetcode.com/problems/top-k-frequent-elements/) |Medium| [Java](./code/lc347.java) | 394 | [Decode String](https://leetcode.com/problems/decode-string/) |Medium| [Java] | 406 | [Queue Reconstruction by Height](https://leetcode.com/problems/queue-reconstruction-by-height/) |Medium| [Java] | 416 | [Partition Equal Subset Sum](https://leetcode.com/problems/partition-equal-subset-sum/) |Medium| [Java] | 437 | [Path Sum III](https://leetcode.com/problems/path-sum-iii/) | Easy |[Java] | 438 | [Find All Anagrams in a String](https://leetcode.com/problems/find-all-anagrams-in-a-string/) | Easy |[Java](./code/lc438.java) | 448 | [Find All Numbers Disappeared in an Array](https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array/) | Easy | [Java] | 461 | [Hamming Distance](https://leetcode.com/problems/hamming-distance/) | Easy |[Java] | 494 | [Target Sum](https://leetcode.com/problems/target-sum/) |Medium|[Java] | 538 | [Convert BST to Greater Tree](https://leetcode.com/problems/convert-bst-to-greater-tree/description/) | Easy |[Java] | 543 | [Diameter of Binary Tree](https://leetcode.com/problems/diameter-of-binary-tree/description/) | Easy | [Java] | 560 | [Subarray Sum Equals K](https://leetcode.com/problems/subarray-sum-equals-k) |Medium| [Java](./code/lc560.java) | 572 | [Subtree of Another Tree](https://leetcode.com/problems/subtree-of-another-tree/description/) | Easy | [Java] | 581 | [Shortest Unsorted Continuous Subarray](https://leetcode.com/problems/shortest-unsorted-continuous-subarray/description/) | Easy | [Java] | 617 | [Merge Two Binary Trees](https://leetcode.com/problems/merge-two-binary-trees/description/) | Easy | [Java] | 621 | [Task Scheduler](https://leetcode.com/problems/task-scheduler) |Medium| [Java] | | 647 | [Palindromic Substrings](https://leetcode.com/problems/palindromic-substrings) |Medium|[Java]