leetcode

Repository for leetcode problems and solutions.

Neetcode

• NeetCode 150

Leetcode Problems

Solved leetcode problems and solutions.

Status	Problem	Difficulty	Source
✅	1. Two Sum	💚 Easy	🔗
✅	2. Add Two Numbers	💛 Medium	🔗
✅	3. Longest Substring Without Repeating Characters	💛 Medium	🔗
✅	4. Median of Two Sorted Arrays	❤️ Hard	🔗
✅	5. Longest Palindromic Substring	💛 Medium	🔗
✅	6. Zigzag Conversion	💛 Medium	🔗
✅	7. Reverse Integer	💛 Medium	🔗
✅	8. String to Integer (atoi)	💛 Medium	🔗
✅	9. Palindrome Number	💚 Easy	🔗
🚧	10. Regular Expression Matching	❤️ Hard	🔗
✅	11. Container With Most Water	💛 Medium	🔗
✅	12. Integer to Roman	💛 Medium	🔗
✅	13. Roman to Integer	💚 Easy	🔗
✅	14. Longest Common Prefix	💚 Easy	🔗
✅	15. 3Sum	💛 Medium	🔗
✅	17. Letter Combinations of a Phone Number	💛 Medium	🔗
✅	19. Remove Nth Node From End of List	💛 Medium	🔗
✅	20. Valid Parentheses	💚 Easy	🔗
✅	21. Merge Two Sorted Lists	💚 Easy	🔗
✅	23. Merge k Sorted Lists	❤️ Hard	🔗
✅	24. Swap Nodes in Pairs	💛 Medium	🔗
✅	25. Reverse Nodes in k-Group	❤️ Hard	🔗
✅	26. Remove Duplicates from Sorted Array	💚 Easy	🔗
✅	27. Remove Element	💚 Easy	🔗
✅	28. Find the Index of the First Occurrence in a String	💚 Easy	🔗
✅	29. Divide Two Integers	💛 Medium	🔗
✅	33. Search in Rotated Sorted Array	💛 Medium	🔗
✅	34. Find First and Last Position of Element in Sorted Array	💛 Medium	🔗
✅	35. Search Insert Position	💚 Easy	🔗
✅	36. Valid Sudoku	💛 Medium	🔗
✅	38. Count and Say	💛 Medium	🔗
✅	39. Combination Sum	💛 Medium	🔗
✅	40. Combination Sum II	💛 Medium	🔗
✅	41. First Missing Positive	❤️ Hard	🔗
✅	42. Trapping Rain Water	❤️ Hard	🔗
✅	46. Permutations	💛 Medium	🔗
✅	47. Permutations II	💛 Medium	🔗
✅	49. Group Anagrams	💛 Medium	🔗
✅	50. Pow(x, n)	💛 Medium	🔗
✅	53. Maximum Subarray	💛 Medium	🔗
✅	54. Spiral Matrix	💛 Medium	🔗
✅	55. Jump Game	💛 Medium	🔗
✅	56. Merge Intervals	💛 Medium	🔗
✅	57. Insert Interval	💛 Medium	🔗
✅	58. Length of Last Word	💚 Easy	🔗
✅	59. Spiral Matrix II	💛 Medium	🔗
✅	61. Rotate List	💛 Medium	🔗
✅	64. Minimum Path Sum	💛 Medium	🔗
✅	65. Valid Number	❤️ Hard	🔗
✅	66. Plus One	💚 Easy	🔗
✅	67. Add Binary	💚 Easy	🔗
✅	69. Sqrt(x)	💚 Easy	🔗
✅	70. Climbing Stairs	💚 Easy	🔗
✅	71. Simplify Path	💛 Medium	🔗
✅	73. Set Matrix Zeroes	💛 Medium	🔗
✅	74. Search a 2D Matrix	💛 Medium	🔗
✅	75. Sort Colors	💛 Medium	🔗
✅	76. Minimum Window Substring	❤️ Hard	🔗
✅	77. Combinations	💛 Medium	🔗
✅	78. Subsets	💛 Medium	🔗
✅	79. Word Search	💛 Medium	🔗
✅	82. Remove Duplicates from Sorted List II	💛 Medium	🔗
✅	83. Remove Duplicates from Sorted List	💚 Easy	🔗
✅	88. Merge Sorted Array	💚 Easy	🔗
✅	90. Subsets II	💛 Medium	🔗
✅	98. Validate Binary Search Tree	💛 Medium	🔗
✅	100. Same Tree	💚 Easy	🔗
✅	102. Binary Tree Level Order Traversal	💛 Medium	🔗
✅	104. Maximum Depth of Binary Tree	💚 Easy	🔗
✅	110. Balanced Binary Tree	💚 Easy	🔗
✅	112. Path Sum	💚 Easy	🔗
✅	118. Pascal's Triangle	💚 Easy	🔗
✅	119. Pascal's Triangle II	💚 Easy	🔗
✅	121. Best Time to Buy and Sell Stock	💚 Easy	🔗
✅	125. Valid Palindrome	💚 Easy	🔗
✅	128. Longest Consecutive Sequence	💛 Medium	🔗
✅	130. Surrounded Regions	💛 Medium	🔗
✅	133. Clone Graph	💛 Medium	🔗
✅	136. Single Number	💚 Easy	🔗
✅	138. Copy List with Random Pointer	💛 Medium	🔗
✅	141. Linked List Cycle	💚 Easy	🔗
✅	142. Linked List Cycle II	💛 Medium	🔗
✅	143. Reorder List	💛 Medium	🔗
✅	144. Binary Tree Preorder Traversal	💚 Easy	🔗
✅	145. Binary Tree Postorder Traversal	💚 Easy	🔗
✅	146. LRU Cache	💛 Medium	🔗
✅	148. Sort List	💛 Medium	🔗
✅	150. Evaluate Reverse Polish Notation	💛 Medium	🔗
✅	151. Reverse Words in a String	💛 Medium	🔗
✅	153. Find Minimum in Rotated Sorted Array	💛 Medium	🔗
✅	155. Min Stack	💛 Medium	🔗
✅	157. Read N Characters Given Read4	💚 Easy	🔗
✅	160. Intersection of Two Linked Lists	💚 Easy	🔗
✅	167. Two Sum II - Input Array Is Sorted	💛 Medium	🔗
✅	169. Majority Element	💚 Easy	🔗
✅	170. Two Sum III - Data structure design	💚 Easy	🔗
✅	171. Excel Sheet Column Number	💚 Easy	🔗
✅	173. Binary Search Tree Iterator	💛 Medium	🔗
✅	175. Combine Two Tables	💚 Easy	🔗
✅	181. Employees Earning More Than Their Managers	💚 Easy	🔗
✅	189. Rotate Array	💛 Medium	🔗
✅	190. Reverse Bits	💚 Easy	🔗
✅	191. Number of 1 Bits	💚 Easy	🔗
✅	197. Rising Temperature	💚 Easy	🔗
✅	198. House Robber	💛 Medium	🔗
✅	199. Binary Tree Right Side View	💛 Medium	🔗
✅	200. Number of Islands	💛 Medium	🔗
✅	202. Happy Number	💚 Easy	🔗
✅	203. Remove Linked List Elements	💚 Easy	🔗
✅	205. Isomorphic Strings	💚 Easy	🔗
✅	206. Reverse Linked List	💚 Easy	🔗
✅	207. Course Schedule	💛 Medium	🔗
✅	208. Implement Trie (Prefix Tree)	💛 Medium	🔗
✅	209. Minimum Size Subarray Sum	💛 Medium	🔗
✅	210. Course Schedule II	💛 Medium	🔗
✅	213. House Robber II	💛 Medium	🔗
✅	215. Kth Largest Element in an Array	💛 Medium	🔗
✅	217. Contains Duplicate	💚 Easy	🔗
✅	219. Contains Duplicate II	💚 Easy	🔗
✅	222. Count Complete Tree Nodes	💚 Easy	🔗
✅	225. Implement Stack using Queues	💚 Easy	🔗
✅	226. Invert Binary Tree	💚 Easy	🔗
✅	228. Summary Ranges	💚 Easy	🔗
✅	229. Majority Element II	💛 Medium	🔗
✅	230. Kth Smallest Element in a BST	💛 Medium	🔗
✅	231. Power of Two	💚 Easy	🔗
✅	232. Implement Queue using Stacks	💚 Easy	🔗
✅	234. Palindrome Linked List	💚 Easy	🔗
✅	235. Lowest Common Ancestor of a Binary Search Tree	💛 Medium	🔗
✅	236. Lowest Common Ancestor of a Binary Tree	💛 Medium	🔗
✅	238. Product of Array Except Self	💛 Medium	🔗
✅	239. Sliding Window Maximum	❤️ Hard	🔗
✅	242. Valid Anagram	💚 Easy	🔗
✅	251. Flatten 2D Vector	💛 Medium	🔗
✅	252. Meeting Rooms	💛 Medium	🔗
✅	253. Meeting Rooms II	💛 Medium	🔗
✅	268. Missing Number	💚 Easy	🔗
✅	271. Encode and Decode Strings	💛 Medium	🔗
✅	281. Zigzag Iterator	💛 Medium	🔗
✅	283. Move Zeroes	💚 Easy	🔗
✅	284. Peeking Iterator	💛 Medium	🔗
✅	286. Walls and Gates	💛 Medium	🔗
✅	287. Find the Duplicate Number	💛 Medium	🔗
✅	289. Game of Life	💛 Medium	🔗
✅	290. Word Pattern	💚 Easy	🔗
✅	295. Find Median from Data Stream	❤️ Hard	🔗
✅	300. Longest Increasing Subsequence	💛 Medium	🔗
✅	303. Range Sum Query - Immutable	💚 Easy	🔗
✅	326. Power of Three	💚 Easy	🔗
✅	338. Counting Bits	💚 Easy	🔗
✅	342. Power of Four	💚 Easy	🔗
✅	344. Reverse String	💚 Easy	🔗
✅	345. Reverse Vowels of a String	💚 Easy	🔗
✅	346. Moving Average from Data Stream	💚 Easy	🔗
✅	347. Top K Frequent Elements	💛 Medium	🔗
✅	348. Design Tic-Tac-Toe	💛 Medium	🔗
✅	353. Design Snake Game	💛 Medium	🔗
✅	355. Design Twitter	💛 Medium	🔗
✅	359. Logger Rate Limiter	💚 Easy	🔗
✅	362. Design Hit Counter	💛 Medium	🔗
✅	374. Guess Number Higher or Lower	💚 Easy	🔗
✅	380. Insert Delete GetRandom O(1)	💛 Medium	🔗
✅	383. Ransom Note	💚 Easy	🔗
✅	389. Find the Difference	💚 Easy	🔗
✅	392. Is Subsequence	💚 Easy	🔗
✅	409. Longest Palindrome	💚 Easy	🔗
✅	412. Fizz Buzz	💚 Easy	🔗
✅	415. Add Strings	💚 Easy	🔗
✅	417. Pacific Atlantic Water Flow	💛 Medium	🔗
✅	424. Longest Repeating Character Replacement	💛 Medium	🔗
✅	442. Find All Duplicates in an Array	💛 Medium	🔗
✅	449. Serialize and Deserialize BST	💛 Medium	🔗
✅	485. Max Consecutive Ones	💚 Easy	🔗
✅	487. Max Consecutive Ones II	💛 Medium	🔗
✅	496. Next Greater Element I	💚 Easy	🔗
✅	498. Diagonal Traverse	💛 Medium	🔗
✅	503. Next Greater Element II	💛 Medium	🔗
✅	507. Perfect Number	💚 Easy	🔗
✅	509. Fibonacci Number	💚 Easy	🔗
✅	543. Diameter of Binary Tree	💚 Easy	🔗
✅	557. Reverse Words in a String III	💚 Easy	🔗
✅	567. Permutation in String	💛 Medium	🔗
✅	572. Subtree of Another Tree	💚 Easy	🔗
✅	605. Can Place Flowers	💚 Easy	🔗
✅	607. Sales Person	💚 Easy	🔗
✅	621. Task Scheduler	💛 Medium	🔗
✅	643. Maximum Average Subarray I	💚 Easy	🔗
✅	692. Top K Frequent Words	💛 Medium	🔗
✅	695. Max Area of Island	💛 Medium	🔗
✅	700. Search in a Binary Tree	💚 Easy	🔗
✅	703. Kth Largest Element in a Stream	💚 Easy	🔗
✅	704. Binary Search	💚 Easy	🔗
✅	724. Find Pivot Index	💚 Easy	🔗
✅	739. Daily Temperatures	💛 Medium	🔗
✅	746. Min Cost Climbing Stairs	💚 Easy	🔗
✅	747. Largest Number At Least Twice of Others	💚 Easy	🔗
✅	821. Shortest Distance to a Character	💚 Easy	🔗
✅	853. Car Fleet	💛 Medium	🔗
✅	875. Koko Eating Bananas	💛 Medium	🔗
✅	876. Middle of the Linked List	💚 Easy	🔗
✅	933. Number of Recent Calls	💚 Easy	🔗
✅	941. Valid Mountain Array	💚 Easy	🔗
✅	973. K Closest Points to Origin	💛 Medium	🔗
✅	977. Squares of a Sorted Array	💚 Easy	🔗
✅	994. Rotting Oranges	💛 Medium	🔗
✅	1009. Complement of Base 10 Integer	💚 Easy	🔗
✅	1046. Last Stone Weight	💚 Easy	🔗
✅	1047. Remove All Adjacent Duplicates In String	💚 Easy	🔗
✅	1137. N-th Tribonacci Number	💚 Easy	🔗
✅	1154. Day of the Year	💚 Easy	🔗
✅	1160. Find Words That Can Be Formed by Characters	💚 Easy	🔗
✅	1166. Design File System	💛 Medium	🔗
✅	1207. Unique Number of Occurrences	💚 Easy	🔗
✅	1229. Meeting Scheduler	💛 Medium	🔗
✅	1265. Print Immutable Linked List in Reverse	💛 Medium	🔗
✅	1290. Convert Binary Number in a Linked List to Integer	💚 Easy	🔗
✅	1295. Find Numbers with Even Number of Digits	💚 Easy	🔗
✅	1346. Check If N and Its Double Exist	💚 Easy	🔗
✅	1351. Count Negative Numbers in a Sorted Matrix	💚 Easy	🔗
✅	1408. String Matching in an Array	💚 Easy	🔗
✅	1431. Kids With the Greatest Number of Candies	💚 Easy	🔗
✅	1448. Count Good Nodes in Binary Tree	💛 Medium	🔗
✅	1475. Final Prices With a Special Discount in a Shop	💚 Easy	🔗
✅	1513. Number of Substrings With Only 1s	💛 Medium	🔗
✅	1523. Count Odd Numbers in an Interval Range	💚 Easy	🔗
✅	1550. Three Consecutive Odds	💚 Easy	🔗
✅	1582. Special Positions in a Binary Matrix	💚 Easy	🔗
✅	1668. Maximum Repeating Substring	💚 Easy	🔗
✅	1768. Merge Strings Alternately	💚 Easy	🔗
✅	1790. Check if One String Swap Can Make Strings Equal	💚 Easy	🔗
✅	1800. Maximum Ascending Subarray Sum	💚 Easy	🔗
✅	1863. Sum of All Subset XOR Totals	💚 Easy	🔗
✅	1876. Substrings of Size Three with Distinct Characters	💚 Easy	🔗
✅	1910. Remove All Occurrences of a Substring	💛 Medium	🔗
✅	1920. Build Array from Permutation	💚 Easy	🔗
✅	1991. Find the Middle Index in Array	💚 Easy	🔗
✅	2011. Final Value of Variable After Performing Operations	💚 Easy	🔗
✅	2016. Maximum Difference Between Increasing Elements	💚 Easy	🔗
✅	2034. Stock Price Fluctuation	💛 Medium	🔗
✅	2043. Simple Bank System	💛 Medium	🔗
✅	2094. Finding 3-Digit Even Numbers	💚 Easy	🔗
✅	2109. Adding Spaces to a String	💛 Medium	🔗
✅	2115. Find All Possible Recipes from Given Supplies	💛 Medium	🔗
✅	2133. Check if Every Row and Column Contains All Numbers	💚 Easy	🔗
✅	2138. Divide a String Into Groups of Size k	💚 Easy	🔗
✅	2154. Keep Multiplying Found Values by Two	💚 Easy	🔗
✅	2185. Counting Words With a Given Prefix	💚 Easy	🔗
✅	2206. Divide Array Into Equal Pairs	💚 Easy	🔗
✅	2215. Find the Difference of Two Arrays	💚 Easy	🔗
✅	2235. Add Two Integers	💚 Easy	🔗
✅	2264. Largest 3-Same-Digit Number in String	💚 Easy	🔗
✅	2273. Find Resultant Array After Removing Anagrams	💚 Easy	🔗
✅	2315. Count Asterisks	💚 Easy	🔗
✅	2336. Smallest Number in Infinite Set	💛 Medium	🔗
✅	2401. Longest Nice Subarray	💛 Medium	🔗
✅	2469. Convert the Temperature	💚 Easy	🔗
✅	2570. Merge Two 2D Arrays by Summing Values	💚 Easy	🔗
✅	2639. Find the Width of Columns of a Grid	💚 Easy	🔗
✅	2648. Generate Fibonacci Sequence	💚 Easy	🔗
✅	2667. Create Hello World Function	💚 Easy	🔗
✅	2703. Return Length of Arguments Passed	💚 Easy	🔗
✅	2796. Repeat String	💚 Easy	🔗
✅	2843. Count Symmetric Integers	💚 Easy	🔗
✅	2894. Divisible and Non-divisible Sums Difference	💚 Easy	🔗
✅	2933. High-Access Employees	💛 Medium	🔗
✅	2942. Find Words Containing Character	💚 Easy	🔗
✅	3000. Maximum Area of Longest Diagonal Rectangle	💚 Easy	🔗
✅	3024. Type of Triangle	💚 Easy	🔗
✅	3136. Valid Word	💚 Easy	🔗
✅	3169. Count Days Without Meetings	💛 Medium	🔗
✅	3264. Final Array State After K Multiplication Operations I	💚 Easy	🔗
✅	3423. Maximum Difference Between Adjacent Elements in a Circular Array	💚 Easy	🔗
✅	3432. Count Partitions with Even Sum Difference	💚 Easy	🔗
✅	3442. Maximum Difference Between Even and Odd Frequency I	💚 Easy	🔗
✅	3452. Sum of Good Numbers	💚 Easy	🔗
✅	3461. Check If Digits Are Equal in String After Operations I	💚 Easy	🔗
✅	3531. Count Covered Buildings	💛 Medium	🔗
✅	3606. Coupon Code Validator	💚 Easy	🔗
✅	3683. Earliest Time to Finish One Task	💚 Easy	🔗