### Array & Hashing\n1. [Two Sum](https://leetcode.com/problems/two-sum/)\n2. [Valid Anagram](https://leetcode.com/problems/valid-anagram/)\n3. [Contains Duplicate](https://leetcode.com/problems/contains-duplicate/)\n4. [Product of Array Except Self](https://leetcode.com/problems/product-of-array-except-self/)\n5. [Maximum Subarray](https://leetcode.com/problems/maximum-subarray/)\n6. [Maximum Product Subarray](https://leetcode.com/problems/maximum-product-subarray/)\n7. [Find Minimum in Rotated Sorted Array](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/)\n8. [Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array/)\n9. [3Sum](https://leetcode.com/problems/3sum/)\n10. [Container With Most Water](https://leetcode.com/problems/container-with-most-water/)\n\n### Two Pointers\n11. [Valid Palindrome](https://leetcode.com/problems/valid-palindrome/)\n12. [3Sum](https://leetcode.com/problems/3sum/)\n13. [Container With Most Water](https://leetcode.com/problems/container-with-most-water/)\n14. [Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water/)\n15. [Best Time to Buy and Sell Stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/)\n16. [Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/)\n17. [Palindromic Substrings](https://leetcode.com/problems/palindromic-substrings/)\n18. [Longest Palindromic Substring](https://leetcode.com/problems/longest-palindromic-substring/)\n19. [Find Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/)\n\n### Sliding Window\n20. [Best Time to Buy and Sell Stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/)\n21. [Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/)\n22. [Longest Repeating Character Replacement](https://leetcode.com/problems/longest-repeating-character-replacement/)\n23. [Permutation in String](https://leetcode.com/problems/permutation-in-string/)\n24. [Minimum Window Substring](https://leetcode.com/problems/minimum-window-substring/)\n25. [Sliding Window Maximum](https://leetcode.com/problems/sliding-window-maximum/)\n\n### Stack\n26. [Valid Parentheses](https://leetcode.com/problems/valid-parentheses/)\n27. [Min Stack](https://leetcode.com/problems/min-stack/)\n28. [Generate Parentheses](https://leetcode.com/problems/generate-parentheses/)\n29. [Daily Temperatures](https://leetcode.com/problems/daily-temperatures/)\n30. [Evaluate Reverse Polish Notation](https://leetcode.com/problems/evaluate-reverse-polish-notation/)\n31. [Largest Rectangle in Histogram](https://leetcode.com/problems/largest-rectangle-in-histogram/)\n32. [Car Fleet](https://leetcode.com/problems/car-fleet/)\n33. [Binary Search Tree Iterator](https://leetcode.com/problems/binary-search-tree-iterator/)\n34. [Basic Calculator II](https://leetcode.com/problems/basic-calculator-ii/)\n\n### Binary Search\n35. [Binary Search](https://leetcode.com/problems/binary-search/)\n36. [Search 2D Matrix](https://leetcode.com/problems/search-a-2d-matrix/)\n37. [Koko Eating Bananas](https://leetcode.com/problems/koko-eating-bananas/)\n38. [Find Minimum in Rotated Sorted Array](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/)\n39. [Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array/)\n40. [Time Based Key-Value Store](https://leetcode.com/problems/time-based-key-value-store/)\n41. [Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/)\n\n### Linked List\n42. [Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/)\n43. [Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/)\n44. [Reorder List](https://leetcode.com/problems/reorder-list/)\n45. [Remove Nth Node From End of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list/)\n46. [Copy List With Random Pointer](https://leetcode.com/problems/copy-list-with-random-pointer/)\n47. [Add Two Numbers](https://leetcode.com/problems/add-two-numbers/)\n48. [Linked List Cycle](https://leetcode.com/problems/linked-list-cycle/)\n49. [Intersection of Two Linked Lists](https://leetcode.com/problems/intersection-of-two-linked-lists/)\n50. [LRU Cache](https://leetcode.com/problems/lru-cache/)\n\n### Trees\n51. [Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree/)\n52. [Same Tree](https://leetcode.com/problems/same-tree/)\n53. [Invert Binary Tree](https://leetcode.com/problems/invert-binary-tree/)\n54. [Binary Tree Maximum Path Sum](https://leetcode.com/problems/binary-tree-maximum-path-sum/)\n55. [Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/)\n56. [Subtree of Another Tree](https://leetcode.com/problems/subtree-of-another-tree/)\n57. [Construct Binary Tree from Preorder and Inorder Traversal](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/)\n58. [Validate Binary Search Tree](https://leetcode.com/problems/validate-binary-search-tree/)\n59. [Kth Smallest Element in a BST](https://leetcode.com/problems/kth-smallest-element-in-a-bst/)\n60. [Lowest Common Ancestor of a Binary Tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/)\n\n### Tries\n61. [Implement Trie (Prefix Tree)](https://leetcode.com/problems/implement-trie-prefix-tree/)\n62. [Design Add and Search Words Data Structure](https://leetcode.com/problems/design-add-and-search-words-data-structure/)\n63. [Word Search II](https://leetcode.com/problems/word-search-ii/)\n\n### Heap / Priority Queue\n64. [Kth Largest Element in an Array](https://leetcode.com/problems/kth-largest-element-in-an-array/)\n65. [Task Scheduler](https://leetcode.com/problems/task-scheduler/)\n66. [Design Twitter](https://leetcode.com/problems/design-twitter/)\n67. [Find Median from Data Stream](https://leetcode.com/problems/find-median-from-data-stream/)\n68. [Merge K Sorted Lists](https://leetcode.com/problems/merge-k-sorted-lists/)\n69. [Top K Frequent Elements](https://leetcode.com/problems/top-k-frequent-elements/)\n\n### Backtracking\n70. [Subsets](https://leetcode.com/problems/subsets/)\n71. [Combination Sum](https://leetcode.com/problems/combination-sum/)\n72. [Permutations](https://leetcode.com/problems/permutations/)\n73. [Word Search](https://leetcode.com/problems/word-search/)\n74. [Palindrome Partitioning](https://leetcode.com/problems/palindrome-partitioning/)\n75. [N-Queens](https://leetcode.com/problems/n-queens/)\n\n### Graphs\n76. [Number of Islands](https://leetcode.com/problems/number-of-islands/)\n77. [Clone Graph](https://leetcode.com/problems/clone-graph/)\n78. [Max Area of Island](https://leetcode.com/problems/max-area-of-island/)\n79. [Pacific Atlantic Water Flow](https://leetcode.com/problems/pacific-atlantic-water-flow/)\n80. [Surrounded Regions](https://leetcode.com/problems/surrounded-regions/)\n81. [Rotting Oranges](https://leetcode.com/problems/rotting-oranges/)\n82. [Course Schedule](https://leetcode.com/problems/course-schedule/)\n83. [Course Schedule II](https://leetcode.com/problems/course-schedule-ii/)\n84. [Alien Dictionary](https://leetcode.com/problems/alien-dictionary/)\n85. [Graph Valid Tree](https://leetcode.com/problems/graph-valid-tree/)\n86. [Number of Connected Components in an Undirected Graph](https://leetcode.com/problems/number-of-connected-components-in-an-undirected-graph/)\n\n### 1-D Dynamic Programming\n87. [Climbing Stairs](https://leetcode.com/problems/climbing-stairs/)\n88. [House Robber](https://leetcode.com/problems/house-robber/)\n89. [House Robber II](https://leetcode.com/problems/house-robber-ii/)\n90. [Longest Palindromic Subsequence](https://leetcode.com/problems/longest-palindromic-subsequence/)\n91. [Palindromic Substrings](https://leetcode.com/problems/palindromic-substrings/)\n92. [Decode Ways](https://leetcode.com/problems/decode-ways/)\n93. [Coin Change](https://leetcode.com/problems/coin-change/)\n94. [Longest Increasing Subsequence](https://leetcode.com/problems/longest-increasing-subsequence/)\n95. [Partition Equal Subset Sum](https://leetcode.com/problems/partition-equal-subset-sum/)\n\n### 2-D Dynamic Programming\n96. [Unique Paths](https://leetcode.com/problems/unique-paths/)\n97. [Longest Common Subsequence](https://leetcode.com/problems/longest-common-subsequence/)\n98. [Word Break](https://leetcode.com/problems/word-break/)\n99. [Combination Sum IV](https://leetcode.com/problems/combination-sum-iv/)\n100. [Minimum Path Sum](https://leetcode.com/problems/minimum-path-sum/)\n101. [Edit Distance](https://leetcode.com/problems/edit-distance/)\n102. [Maximal Square](https://leetcode.com/problems/maximal-square/)\n103. [Burst Balloons](https://leetcode.com/problems/burst-balloons/)\n\n### Greedy\n104. [Maximum Subarray](https://leetcode.com/problems/maximum-subarray/)\n105. [Jump Game](https://leetcode.com/problems/jump-game/)\n106. [Jump Game II](https://leetcode.com/problems/jump-game-ii/)\n107. [Gas Station](https://leetcode.com/problems/gas-station/)\n108. [Hand of Straights](https://leetcode.com/problems/hand-of-straights/)\n109. [Merge Intervals](https://leetcode.com/problems/merge-intervals/)\n110. [Insert Interval](https://leetcode.com/problems/insert-interval/)\n111. [Non-overlapping Intervals](https://leetcode.com/problems/non-overlapping-intervals/)\n112. [Meeting Rooms](https://leetcode.com/problems/meeting-rooms/)\n113. [Meeting Rooms II](https://leetcode.com/problems/meeting-rooms-ii/)\n\n### Intervals\n114. [Merge Intervals](https://leetcode.com/problems/merge-intervals/)\n115. [Insert Interval](https://leetcode.com/problems/insert-interval/)\n116. [Non-overlapping Intervals](https://leetcode.com/problems/non-overlapping-intervals/)\n117. [Meeting Rooms](https://leetcode.com/problems/meeting-rooms/)\n118. [Meeting Rooms II](https://leetcode.com/problems/meeting-rooms-ii/)\n\n### Math & Geometry\n119. [Rotate Image](https://leetcode.com/problems/rotate-image/)\n120. [Spiral Matrix](https://leetcode.com/problems/spiral-matrix/)\n121. [Set Matrix Zeroes](https://leetcode.com/problems/set-matrix-zeroes/)\n122. [Happy Number](https://leetcode.com/problems/happy-number/)\n123. [Plus One](https://leetcode.com/problems/plus-one/)\n124. [Pow(x, n)](https://leetcode.com/problems/powx-n/)\n125. [Multiply Strings](https://leetcode.com/problems/multiply-strings/)\n126. [Rotate Array](https://leetcode.com/problems/rotate-array/)\n\n### Bit Manipulation\n127. [Single Number](https://leetcode.com/problems/single-number/)\n128. [Number of 1 Bits](https://leetcode.com/problems/number-of-1-bits/)\n129. [Counting Bits](https://leetcode.com/problems/counting-bits/)\n130. [Reverse Bits](https://leetcode.com/problems/reverse-bits/)\n131. [Missing Number](https://leetcode.com/problems/missing-number/)\n132. [Sum of Two Integers](https://leetcode.com/problems/sum-of-two-integers/)\n\n### Advanced Topics (Hard)\n133. [Reverse Nodes in k-Group](https://leetcode.com/problems/reverse-nodes-in-k-group/)\n134. [Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/)\n135. [Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water/)\n136. [Longest Valid Parentheses](https://leetcode.com/problems/longest-valid-parentheses/)\n137. [Regular Expression Matching](https://leetcode.com/problems/regular-expression-matching/)\n138. [Wildcard Matching](https://leetcode.com/problems/wildcard-matching/)\n139. [Word Ladder](https://leetcode.com/problems/word-ladder/)\n140. [Word Ladder II](https://leetcode.com/problems/word-ladder-ii/)\n141. [Edit Distance](https://leetcode.com/problems/edit-distance/)\n142. [Maximum Flow (Not on LeetCode)](https://en.wikipedia.org/wiki/Maximum_flow_problem)\n143. [Insert Interval](https://leetcode.com/problems/insert-interval/)\n144. [Serialize and Deserialize Binary Tree](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/)\n145. [Alien Dictionary](https://leetcode.com/problems/alien-dictionary/)\n146. [Palindrome Pairs](https://leetcode.com/problems/palindrome-pairs/)\n147. [Maximal Rectangle](https://leetcode.com/problems/maximal-rectangle/)\n148. [First Missing Positive](https://leetcode.com/problems/first-missing-positive/)\n149. [Largest Rectangle in Histogram](https://leetcode.com/problems/largest-rectangle-in-histogram/)\n150. [N-Queens II](https://leetcode.com/problems/n-queens-ii/)\n\nCheers !!!

Array & Hashing\n1. Two Sum\n2. Valid Anagram\n3. Contains Duplicate\n4. Product of Array Except Self\n5. Maximum Subarray\n6. Maximum Product Subarray\n7. Find