Leetcode

LeetCode Problems by Topic

Array and String Manipulation

• 3. Longest Substring Without Repeating Chars
• 5. Longest Palindromic Substring
• 6. Zigzag Conversion
• 14. Longest Common Prefix
• 26. Remove Duplicates From Sorted Array
• 28. Find Index of First Occurence in String
• 31. Next Permutation
• 43. Multiply Strings
• 58. Length of Last Word
• 80. Remove Duplicates from Array
• 88. Merge Sorted Array
• 125. Valid Palindrome
• 189. Rotate Array
• 214. Shortest Palindrome
• 424. Longest Repeating Character Replacement
• 647. Count Palindromic Substrings
• 2109. Add Spaces to String
• 2825. Make String a Substring Using Cyclic Increments

Binary Search and Sorted Arrays

• 33. Search in a Rotated Array
• 34. Find First and Last Position of Element in Sorted Array
• 35. Search Insert Position
• 81. Search in a Rotated Array 2
• 153. Find Minimum in a Rotated Array
• 154. Find Minimum in Sorted Rotated Array 2
• 162. Find Peak Element

Dynamic Programming

• 10. Regex Matching
• 44. Wildcard Matching
• 46. Permutations
• 47. Permutations
• 50. Pow(x, n)
• 62. Unique Paths
• 70. Climbing Stairs
• 91. Decode Ways
• 139. Word Break
• 152. Maximum Product Subarray
• 198. House Robber
• 213. House Robber 2
• 221. Maximal Square
• 300. Longest Increasing Subsequence
• 322. Coin Change
• 494. Target Sum
• 1014. Best Sightseeing Pair
• 1143. Longest Common Subsequence

Tree and Graph Problems

• 102. Binary Tree Level Order Traversal
• 105. Construct Binary Tree from Pre and Inorder
• 108. Convert Array to BST
• 130. Surrounded Regions
• 124. Binary Tree Max Path Sum
• 133. Clone Graph
• 200. Number of Islands
• 207. Course Schedule
• 230. Kth Smallest Element in BST
• 235. Lowest Common Ancestor of BST
• 236. Lowest Common Ancestor of a Binary Tree
• 297. Serialize and Deserialize Tree
• 310. Minimum Height Tree
• 417. Pacific Atlantic Water Flow
• 515. Find Largest Value in Each Tree Row

Linked Lists

• 2. Add Two Numbers
• 21. Merge K Sorted Lists
• 23. Merge K Sorted Lists
• 24. Swap Nodes in Pairs
• 25. Reverse Nodes in K Groups
• 61. Rotate List
• 142. Linked List Cycle
• 143. Reorder List
• 160. Intersection of Two Linked Lists

Hash Tables and Sets

• 49. Group Anagrams
• 128. Longest Consecutive Sequence
• 169. Majority Element
• 242. Valid Anagram
• 347. Top K Frequent Elements

Stack and Queue

• 20. Valid Parantheses
• 22. Generate Parentheses
• 32. Longest Valid Parentheses
• 71. Simplify Path

Backtracking

• 39. Combination Sum
• 40. Combination Sum 2
• 51. N Queens
• 52. N Queens II
• 212. Word Search 2

Two Pointers and Sliding Window

• 15. 3Sum
• 16. 3Sum Closest
• 18. 4Sum
• 30. Substring with Concatenation of All Words
• 76. Minimum Window Substring

Math and Numbers

• 9. Palindrome Number
• 12. Integer To Roman
• 29. Divide Two Integers
• 36. Valid Sudoku
• 41. First Missing Positive
• 2177. Consecutive Numbers Sum to Integer
• 17. Letter Combinations Of A Phone Number

Intervals

• 56. Merge Intervals
• 57. Insert Interval
• 435. Merge Overlapping Intervals

Data Structure Design

• 208. Implement Trie
• 211. Design Add and Search Words DS
• 295. Find Median from Data Stream
• 398. Random Pick Index

Greedy

• 42. Trapping Rain Water
• 45. Jump Game 2
• 55. Jump Game
• 122. Best Time to Buy and Sell Stock 2

Miscellaneous

• 38. Count and Say
• 1346. Check if N and Double Exist
• 1455. Check if a Word Occurs as a Prefix of Any Word in a Sentence
• 2337. Move Pieces to Obtain String
• 2554. Maximum Number of Integers to Choose from a Range I
• 2558. Take Gifts from Richest Pile
• 78. Subsets
• 89. Gray Code
• 90. Subsets2
• 37. Sudoku Solver
• 1639. Number Of Ways To Form A Target String From Word Dictionary
• 1639. Number Of Ways To Form A Target String Given A Dictionary
• 59. Spiral Matrix2
• 60. Permutation Sequence
• 151. Reverse Words In A String
• 334. Increasing Triplet Subsequence
• 862. Shortest Subarray With Sum At Least K
• 345. Reverse Vowels Of A String
• 394. Decode String
• 450. Delete Node In A B S T
• 605. Can Place Flowers
• 649. Dota2 Senate
• 735. Asteroid Collision
• 1422. Max Score After Splitting A String
• 1431. Kids With Greatest Number Of Candies
• 1657. Determine If Two Strings Are Close
• 1732. Find Highest Altitude
• 2126. Destroying Asteroids
• 2352. Qual Row And Column Pairs
• 2930. Remove Stars From String
• 215. Kth Largest Element In An Array
• 328. Odd Even Linked List
• 547. Number Of Provinces
• 841. Keys And Rooms
• 994. Rotting Oranges
• 1466. Reorder Routes To Make All Paths Lead To The City Zero
• 1926. Nearest Exit From Entrance In Maze
• 2095. Delete The Middle Node Of A Linked List
• 2270. Number Of Ways To Split Array
• 2336. Smallest Number In An Infinite Set
• 2542. Maximum Subsequence Score
• 2559. Count Vowel Strings In Ranges
• 216. Combination Sum3
• 374. Guess Number Higher Or Lower
• 746. Min Cost Climbing Stairs
• 790. Domino And Tiling
• 875. Koko Eating Bananas
• 1137. Nth Tribonacci Number
• 2300. Successful Pairs Of Spells And Potions
• 2462. Total Cost To Hire K Workers
• 1769. Minimum Number Of Operations To Move All Balls To Each Box
• 1930. Unique Length3 Palindrome Subsequences
• 2381. Shifting Letters2
• 72. Edit Distance
• 135. Candy
• 136. Single Number
• 206. Reverse A Linked List
• 274. H Index
• 283. Move Zeroes
• 338. Counting Bits
• 452. Minimum Number Of Arrows To Burst Balloons
• 714. Best Time To Buy And Sell Stock With Transaction Fee
• 724. Find Pivot Index
• 739. Daily Temperatures
• 901. Online Stock Span
• 933. Number Of Recent Calls
• 1207. Unique Number Of Occurences
• 1268. Search Suggestions System
• 1408. String Matching In An Array
• 2130. Maximum Twin Sum Of A Linked List
• 2215. Find The Difference Of Two Arrays

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