<!-- #### <span style="color: green">Easy</span> #### <span style="color: orange">Medium</span> #### <span style="color: red">Hard</span> --> # LeetCode Solution Approach The LeetCode solution I've made will be a list of articles that each article contains 100 problems. All of them are written using Python3, some of them includes both the most common solutions and advanced solutions: *\* Use `CTRL+F` to fast-forward to the target problem.* ### Algorithm categories ↓ <hr> <!-- ## Maching Problems --> ## Graph/DFS/BFS/Heap Problems #### <span style="color: green">Easy</span> - [94. Binary Tree Inorder Traversal](https://hackmd.io/@dANNy1209/BJrfzwb4eg) - [1971. Find if Path Exists in Graph](https://hackmd.io/@dANNy1209/rJnuf7tmll) #### <span style="color: orange">Medium</span> - [114. Flatten Binary Tree to Linked List](https://hackmd.io/@dANNy1209/SyhfEOZNgg) - [116. Populating Next Right Pointers in Each Node](https://hackmd.io/@dANNy1209/H1HFKKM4ge) - [130. Surrounded Regions](https://hackmd.io/@dANNy1209/rJUDmAWdee) - [133. Clone Graph](https://hackmd.io/@dANNy1209/B1dRy5aXex) - [200. Number of Islands](https://hackmd.io/@dANNy1209/BkDbb50Xex) - [207. Course Schedule](https://hackmd.io/@dANNy1209/BkwNrlxVle) - [230. Kth Smallest Element in a BST](https://hackmd.io/@dANNy1209/HJKnl5zEge) - [341. Flatten Nested List Iterator](https://hackmd.io/@dANNy1209/rJe5zJVEgg) - [378. Kth Smallest Element in a Sorted Matrix](https://hackmd.io/@dANNy1209/rJZCz_hwxg) - [399. Evaluate Division](https://hackmd.io/@dANNy1209/H1OAJdlugl) - [417. Pacific Atlantic Water Flow](https://hackmd.io/@dANNy1209/BJ2QRgRPeg) - [419. Battleships in a Board](https://hackmd.io/@dANNy1209/Sy1ah2zNgg) - [1038. Binary Search Tree to Greater Sum Tree](https://hackmd.io/@dANNy1209/B1QOuGFree) - [1261. Find Elements in a Contaminated Binary Tree](https://hackmd.io/@dANNy1209/rJwGXRuUel) - [1302. Deepest Leaves Sum](https://hackmd.io/@dANNy1209/B1eUGHfIlx) - [1315. Sum of Nodes with Even-Valued Grandparent](https://hackmd.io/@dANNy1209/BJg-yZLLll) - [2265. Count Nodes Equal to Average of Subtree](https://hackmd.io/@dANNy1209/HJZlRA3Sxg) - [2415. Reverse Odd Levels of Binary Tree](https://hackmd.io/@dANNy1209/HypXG07rxx) #### <span style="color: red">Hard</span> - [1255. Maximum Score Words Formed by Letters](https://hackmd.io/@dANNy1209/SJHfABAEgx) ## Greedy Algorithm #### <span style="color: green">Easy</span> - [455. Assign Cookies](https://hackmd.io/@dANNy1209/S1PeHBYQee) #### <span style="color: orange">Medium</span> - [45. Jump Game II](https://hackmd.io/@dANNy1209/HyMvnRHvxx) - [55. Jump Game](https://hackmd.io/@dANNy1209/BkUfjbzwxl) - [56. Merge Intervals](https://hackmd.io/@dANNy1209/ryO3OA07lx) - [106. Construct Binary Tree from Inorder and Postorder Traversal](https://hackmd.io/@dANNy1209/rJskG0VIle) - [122. Best Time to Buy and Sell Stock II](https://hackmd.io/@dANNy1209/r1uz5k4Eee) - [134. Gas Station](https://hackmd.io/@dANNy1209/B1-1nAbOxx) - [435. Non-overlapping Intervals](https://hackmd.io/@dANNy1209/S1WkugbVxg) - [452. Minimum Number of Arrows to Burst Balloons](https://hackmd.io/@dANNy1209/SJ7Ed7S4lx) - [621. Task Scheduler](https://hackmd.io/@dANNy1209/HyN7uEB4ee) - [763. Partition Labels](https://hackmd.io/@dANNy1209/BJWMTa2Lgx) - [807. Max Increase to Keep City Skyline](https://hackmd.io/@dANNy1209/SJi0UxSBeg) - [1282. Group the People Given the Group Size They Belong To](https://hackmd.io/@dANNy1209/Hk8XISHNgx) - [1561. Maximum Number of Coins You Can Get](https://hackmd.io/@dANNy1209/HJ1bwypHle) - [1605. Find Valid Matrix Given Row and Column Sums](https://hackmd.io/@dANNy1209/H1GD4uzIxg) - [1689. Partitioning Into Minimum Number Of Deci-Binary Numbers](https://hackmd.io/@dANNy1209/S1Ld1BrEgl) - [2294. Partition Array Such That Maximum Difference Is K](https://hackmd.io/@dANNy1209/BJBu3z8Ile) - [2375. Construct Smallest Number From DI String](https://hackmd.io/@dANNy1209/SJ-uCv5Slg) #### <span style="color: red">Hard</span> - [42. Trapping Rain Water](https://hackmd.io/@dANNy1209/Hk1J5t2Pel) - [410. Split Array Largest Sum](https://hackmd.io/@dANNy1209/SkeNoK8Vee) - [502. IPO](https://hackmd.io/@dANNy1209/H1LktdINxg) ## Divide and Conquer #### <span style="color: green">Easy</span> - [88. Merge Sorted Array](https://hackmd.io/@dANNy1209/rym0pBtQel) #### <span style="color: orange">Medium</span> - [95. Unique Binary Search Trees II](https://hackmd.io/@dANNy1209/rJhNxNydxg) - [105. Construct Binary Tree from Preorder and Inorder Traversal](https://hackmd.io/@dANNy1209/HydpD6j4gg) - [109. Convert Sorted List to Binary Search Tree](https://hackmd.io/@dANNy1209/H1Hwq-rHlg) - [148. Sort List](https://hackmd.io/@dANNy1209/SkHR_baBxx) - [215. Kth Largest Element in an Array](https://hackmd.io/@dANNy1209/r1gsOVWNel) - [347. Top K Frequent Elements](https://hackmd.io/@dANNy1209/B1MtBAoElg) - [395. Longest Substring with At Least K Repeating Characters](https://hackmd.io/@dANNy1209/ryg-cYedel) - [427. Construct Quad Tree](https://hackmd.io/@dANNy1209/S1YgoCwNel) - [558. Logical OR of Two Binary Grids Represented as Quad-Trees](https://hackmd.io/@dANNy1209/HkzFcwyvxe) - [654. Maximum Binary Tree](https://hackmd.io/@dANNy1209/Hk7bGhUEgg) - [889. Construct Binary Tree from Preorder and Postorder Traversal](https://hackmd.io/@dANNy1209/ry4Ml_qVel) - [912. Sort an Array](https://hackmd.io/@dANNy1209/r14U8XILgx) - [973. K Closest Points to Origin](https://hackmd.io/@dANNy1209/SJC-uY9Elg) - [1382. Balance a Binary Search Tree](https://hackmd.io/@dANNy1209/SJHCM3v4ee) - [1738. Find Kth Largest XOR Coordinate Value](https://hackmd.io/@dANNy1209/HJH34uqrgl) - [3537. Fill a Special Grid](https://hackmd.io/@dANNy1209/S1AeWedNll) ## Dynamic Programming #### <span style="color: green">Easy</span> - [70. Climbing Stairs](https://hackmd.io/@dANNy1209/Syc7Rd67el) - [118. Pascal's Triangle](https://hackmd.io/@dANNy1209/S111tOMrlg) - [338. Counting Bits](https://hackmd.io/@dANNy1209/Sym3muzrxe) #### <span style="color: orange">Medium</span> - [53. Maximum Subarray](https://hackmd.io/@dANNy1209/rkWnoA2Igx) - [62. Unique Paths](https://hackmd.io/@dANNy1209/rksuZJUwel) - [131. Palindrome Partitioning](https://hackmd.io/@dANNy1209/Sk0TZICHxl) - [152. Maximum Product Subarray](https://hackmd.io/@dANNy1209/BJi8OZUwex) - [241. Different Ways to Add Parentheses](https://hackmd.io/@dANNy1209/BJx-upsHlx) - [300. Longest Increasing Subsequence](https://hackmd.io/@dANNy1209/r1Bj_sCmxe) - [322. Coin Change](https://hackmd.io/@dANNy1209/H1gOHGbEll) - [542. 01 Matrix](https://hackmd.io/@dANNy1209/BykxqSyuee) - [647. Palindromic Substrings](https://hackmd.io/@dANNy1209/SkRP1VUIle) - [894. All Possible Full Binary Trees](https://hackmd.io/@dANNy1209/H1hcPHp4gg) - [983. Minimum Cost For Tickets](https://hackmd.io/@dANNy1209/HJJ8napPex) - [1043. Partition Array for Maximum Sum](https://hackmd.io/@dANNy1209/SJuYBvfHxx) - [1140. Stone Game II](https://hackmd.io/@dANNy1209/Sk_EjZFHex) - [1186. Maximum Subarray Sum with One Deletion](https://hackmd.io/@dANNy1209/r1K_iHiweg) - [1277. Count Square Submatrices with All Ones](https://hackmd.io/@dANNy1209/SJtD_mZBxe) - [1638. Count Substrings That Differ by One Character](https://hackmd.io/@dANNy1209/B1F9jkS8lx) - [1641. Count Sorted Vowel Strings](https://hackmd.io/@dANNy1209/SJisnGWSxe) - [1884. Egg Drop With 2 Eggs and N Floors](https://hackmd.io/@dANNy1209/Skho53mSlx) ## Hash Table Problems #### <span style="color: orange">Medium</span> - [49. Group Anagrams](https://hackmd.io/@dANNy1209/BJ-P71GOge) ## Miscellaneous #### <span style="color: green">Easy</span> - [704. Binary Search](https://hackmd.io/@dANNy1209/rJH8o0yEge) ## Uncategorized - [Problems through 1 ~ 100](https://hackmd.io/@dANNy1209/BJ3k4E60C)