- 7. Reverse Integer
- 412. Fizz Buzz
- 976. Largest Perimeter Triangle
- 66. Plus One
- 67. Add Binary [Solved]
- 3110. Score of a String[Solved]
- 1512. Number of Good Pairs[Solved]
- 1822. Sign of the Product of an Array[Solved]
- 3190. Find Minimum Operations to Make All Elements Divisible by Three[Solved]
- 1588. Sum of All Odd Length Subarrays[Solved]
- 1863. Sum of All Subset XOR Totals
- 485. Max Consecutive Ones
- 13. Roman to Integer
- Two Sum
- Reverse A String
- Squares of sorted array
- 3 Sum
- Sort colors - try with 2 pointers
- reverse words in a string
- 4sum - try with 2 points
- move zeros
- Take K Character [Unsolved]
- 349. Intersection of Two Arrays
- 350. Intersection of Two Arrays II
- 386. Lexicographical Numbers
- Find missing elements of a range
- 287. Find the Duplicate Number
- 179. Largest Number[VVI]
- 303. Range Sum Query - Immutable[Unsolved]
- 345. Reverse Vowels of a String[Solved]
- 557. Reverse Words in a String III
- 2778. Sum of Squares of Special Elements [Unsolved]
- Valid Anagram
- Contains Duplicate
- 2 sum and 2sum 2 with hashing
- 2357. Make Array Zero by Subtracting Equal Amounts
- 49. Group Anagrams [VVI]
- Find Missing And Repeating
- 387. First Unique Character in a String
- 169. Majority Element[Unsolved]
- 238. Product of Array Except Self
- selection sort, bubble sort, insertion sort, merge sort, quick sort
- 88. Merge Sorted Array
- min cost to remove all elements such that cost to remove one element is sum of array
- Inversion count
- 315. Count of Smaller Numbers After Self [VVI - Solved]
- Quick Sort Algorithm
- Implement partition algorithm and then modify it to make quick sort (randomised)
- Binary Search
- Lower Bound
- Upper Bound
- 34. Find First and Last Position of Element in Sorted Array
- Smaller or equal elements
- Search 2d Matrix
- Search insert position
- Guess Number Higher or lower
- Arranging Coins
- Valid Perfect Square
- 540. Single Element in a Sorted Array
- 69. Sqrt(x)
- Count Element Occurence
- 33. Search in Rotated Sorted Array
- 162. Find Peak Element
- 153. Find Minimum in Rotated Sorted Array
- 875. Koko Eating Bananas [VVI - Solved]
- 2300. Successful Pairs of Spells and Potions [VVI - Solved]
- 1011. Capacity To Ship Packages Within D Days [VVI - Solved]
- 2616. Minimize the Maximum Difference of Pairs [VVI]
- 410. Split Array Largest Sum [VVI]
- Painter's Partition Problem [VVI - Solved]
- Painter's Partition Problem with modification
- Allocate Books [Unsolved]
- Allocate Books CS [Unsolved]
- 852. Peak Index in a Mountain Array
- 81. Search in Rotated Sorted Array II
- 2426. Number of Pairs Satisfying Inequality [VVI - Solved]
- 4. Median of Two Sorted Arrays
- Red Zone [Unsolved]
- Additional Binary Search's Problems [Unsolved]
- Implement bubble sort using recursion without any single loop
- Implement selection sort using recursion [Unsolved]
- 509. Fibonacci Number
- 1137. N-th Tribonacci Number
- 322. Coin Change
- 279. Perfect Squares
- 983. Minimum Cost For Tickets
- 120. Triangle
- 377. Combination Sum IV
- 300. Longest Increasing Subsequence
- 1137. N-th Tribonacci Number
- 413. Arithmetic Slices
- 386. Lexicographical Numbers
- 1143. Longest Common Subsequence
- 516. Longest Palindromic Subsequence [VVI]
- 188. Best Time to Buy and Sell Stock IV
- N-th Fibonacci Number
- 1137. N-th Tribonacci Number
- Friends Pairing Problem
- 322. Coin Change
- 279. Perfect Squares
- 983. Minimum Cost For Tickets
- 120. Triangle
- 377. Combination Sum IV
- 673. Number of Longest Increasing Subsequence
- 300. Longest Increasing Subsequence
- 1137. N-th Tribonacci Number
- 413. Arithmetic Slices
- 446. Arithmetic Slices II - Subsequence [VVI - DP with Hash Map]
- 1143. Longest Common Subsequence [VVI]
- 516. Longest Palindromic Subsequence [VVI]
- 188. Best Time to Buy and Sell Stock IV
- 123. Best Time to Buy and Sell Stock III [Unsolved]
- 122. Best Time to Buy and Sell Stock II [Unsolved]
- 70. Climbing Stairs [Solved]
- 746. Min Cost Climbing Stairs [Unsolved]
- 198. House Robber [Unsolved]
- 740. Delete and Earn [Unsolved]
- 64. Minimum Path Sum [Unsolved]
- 72. Edit Distance [Unsolved]
- 62. Unique Paths [Unsolved]
- 63. Unique Paths II [Unsolved]
- Paint House [Unsolved]
- Paint House II [Unsolved]
- Linked List Implementation
- 707. Design Linked List [VVI]
- Design Doubly Linked List
- Design Circular Linked List [Unsolved]
- 1472. Design Browser History [VVI]
- 83. Remove Duplicates from Sorted List
- 19. Remove Nth Node From End of List [VVI]
- 1721. Swapping Nodes in a Linked List
- 86. Partition List [VVI]
- 876. Middle of the Linked List[Solved]
- 206. Reverse Linked List [VVI - Unsolved]
- 2130. Maximum Twin Sum of a Linked List[Unsolved - VVI]
- 25. Reverse Nodes in k-Group [Unsolved]
- 2. Add Two Numbers [Unsolved]
- 138. Copy List with Random Pointer [Unsolved]
- 21. Merge Two Sorted Lists [Unsolved]
- 160. Intersection of Two Linked Lists [Unsolved]
- 147. Insertion Sort List [Unsolved]
- 146. LRU Cache [VVI - Solved]
- Stack Implementation using Array
- Stack Implementation Linked List
- 2390. Removing Stars From a String
- 735. Asteroid Collision[VVI]
- 895. Maximum Frequency Stack [VVI - Solved]
- 20. Valid Parentheses
- 1441. Build an Array With Stack Operations
- 844. Backspace String Compare
- Stack using queue - Push efficient [Solved]
- Stack using queue - pop efficient [Solved]
- 71. Simplify Path [Unsolved]
- 84. Largest Rectangle in Histogram [Unsolved]
- 907. Sum of Subarray Minimums [VVI - Solved]
- 155. Min Stack [Solved]
- Stock Span Problem [Unsolved]
- Reverse a Stack [Unsolved]
- 1047. Remove All Adjacent Duplicates In String [Solved]
- Queue Implementation using Array
- Design Queue using Linked List
- 1670. Design Front Middle Back Queue [VVI]
- 232. Implement Queue using Stacks [VVI]
- 622. Design Circular Queue [VVI]
- Design Deque using Linked List
- Design Deque using DLL
- 239. Sliding Window Maximum [VVI - Solved]
- 134. Gas Station [Unsolved]
- What is Sliding Window ?
- 219. Contains Duplicate II[Unsolved]
- 1652. Defuse the Bomb
- 3. Longest Substring Without Repeating Characters[VVI]
- Design Generic Tree(N-ary Tree) [Solved]
- 102. Binary Tree Level Order Traversal [Solved]
- 144. Binary Tree Preorder Traversal [Solved]
- 145. Binary Tree Postorder Traversal [Solved]
- 94. Binary Tree Inorder Traversal [Solved]
- 226. Invert Binary Tree [Solved]
- 104. Maximum Depth of Binary Tree [Solved]
- 543. Diameter of Binary Tree [Solved]
- 110. Balanced Binary Tree [Solved]
- 129. Sum Root to Leaf Numbers [Solved]
- 513. Find Bottom Left Tree Value [Unsolved]
- 515. Find Largest Value in Each Tree Row [Solved]
- 652. Find Duplicate Subtrees [VVI - Solved]
- 662. Maximum Width of Binary Tree [Solved]
- 951. Flip Equivalent Binary Trees [Solved]
- 337. House Robber III [VVI - Solved]
- 606. Construct String from Binary Tree [VVI - Solved]
- 637. Average of Levels in Binary Tree [Solved]
- 107. Binary Tree Level Order Traversal II [Solved]
- 993. Cousins in Binary Tree [Solved]
- 103. Binary Tree Zigzag Level Order Traversal [Unsolved]
- 199. Binary Tree Right Side View [Unsolved]
- 297. Serialize and Deserialize Binary Tree [Unsolved]
- 572. Subtree of Another Tree [Unsolved]
- 617. Merge Two Binary Trees [Unsolved]
- 105. Construct Binary Tree from Preorder and Inorder Traversal [Unsolved]
- 236. Lowest Common Ancestor of a Binary Tree [Unsolved]
- 979. Distribute Coins in Binary Tree[Unsolved]
- 124. Binary Tree Maximum Path Sum [VVI - Solved]
- 701. Insert into a Binary Search Tree [VVI - Solved]
- 700. Search in a Binary Search Tree [Solved]
- 450. Delete Node in a BST [VVI - Solved]
- 230. Kth Smallest Element in a BST[Solved]
- 109. Convert Sorted List to Binary Search Tree[VVI - Solved]
- 98. Validate Binary Search Tree[Solved]
- 1038. Binary Search Tree to Greater Sum Tree[Solved]
- 538. Convert BST to Greater Tree[Solved]
- 1307 · Verify Preorder Sequence in Binary Search Tree[Unsolved]
- 894. All Possible Full Binary Trees[Unsolved]
- 669. Trim a Binary Search Tree[Unsolved]
- 1569. Number of Ways to Reorder Array to Get Same BST[Unsolved]
- Implement your own Hashing function[Solved]
- 706. Design HashMap[VVI - Solved]
- 290. Word Pattern
- 383. Ransom Note[Unsolved]
- 409. Longest Palindrome
- 771. Jewels and Stones
- 1160. Find Words That Can Be Formed by Characters[VVI]
- 1189. Maximum Number of Balloons[VVI]
- 2085. Count Common Words With One Occurrence
- 705. Design HashSet
- 1207. Unique Number of Occurrences
- 1748. Sum of Unique Elements
- 1331. Rank Transform of an Array
- 1365. How Many Numbers Are Smaller Than the Current Number[VVI]
- 2215. Find the Difference of Two Arrays[VVI]
- 1399. Count Largest Group[VVI]
- 1832. Check if the Sentence Is Pangram[VVI]
- 1941. Check if All Characters Have Equal Number of Occurrences
- 2418. Sort the People
- 3146. Permutation Difference between Two Strings
- 3289. The Two Sneaky Numbers of Digitville
- 2441. Largest Positive Integer That Exists With Its Negative
- 1436. Destination City
- 1636. Sort Array by Increasing Frequency
- 3184. Count Pairs That Form a Complete Day I
- 2053. Kth Distinct String in an Array
- 2006. Count Number of Pairs With Absolute Difference K
- 1346. Check If N and Its Double Exist
- 2325. Decode the Message[VVI]
- 3162. Find the Number of Good Pairs I
- 3005. Count Elements With Maximum Frequency
- 3120. Count the Number of Special Characters I
- 3090. Maximum Length Substring With Two Occurrences
- 1796. Second Largest Digit in a String
- 3396. Minimum Number of Operations to Make Elements in Array Distinct
- 1128. Number of Equivalent Domino Pairs
- 2729. Check if The Number is Fascinating
- 1394. Find Lucky Integer in an Array
- 1742. Maximum Number of Balls in a Box
- 1876. Substrings of Size Three with Distinct Characters
- 2341. Maximum Number of Pairs in Array
- 961. N-Repeated Element in Size 2N Array
- 2367. Number of Arithmetic Triplets
- 697. Degree of an Array
- 205. Isomorphic Strings
- 2540. Minimum Common Value
- 1935. Maximum Number of Words You Can Type
- 953. Verifying an Alien Dictionary
- 2309. Greatest English Letter in Upper and Lower Case
- 2062. Count Vowel Substrings of a String
- 2784. Check if Array is Good
- 2283. Check if Number Has Equal Digit Count and Digit Value
- 3438. Find Valid Pair of Adjacent Digits in String
- 599. Minimum Index Sum of Two Lists
- 3442. Maximum Difference Between Even and Odd Frequency I
- 2956. Find Common Elements Between Two Arrays
- 2996. Smallest Missing Integer Greater Than Sequential Prefix Sum
- 2913. Subarrays Distinct Element Sum of Squares I
- 1805. Number of Different Integers in a String
- 208. Implement Trie (Prefix Tree)[Solved]
- 421. Maximum XOR of Two Numbers in an Array[VVI - Solved]
- 211. Design Add and Search Words Data Structure [Unsolved]
- Implement all Important AVL Tree methods[Solved]
- Left rotation
- Right rotation
- Insert in AVL Tree
- Delete in AVL Tree[Unsolved]
- Implement your own Heaps [VVI - Solved]
- Heap Sort Implementation [Solved]
- Implement your own Priority Queue using Heap's property [Solved]
- 215. Kth Largest Element in an Array [Solved]
- 973. K Closest Points to Origin [VVI - Solved]
- 23. Merge k Sorted Lists [VVI - Solved]
- 786. K-th Smallest Prime Fraction[Solved]
- 857. Minimum Cost to Hire K Workers[VVI]
- Merge K Sorted Arrays[Unsolved]
- 295. Find Median from Data Stream[Unsolved]
- Build Min Heap[Unsolved]
- 767. Reorganize String[Unsolved]
- Adjacency List of Graph
- Adjacency Matrix of Graph
- 1971. Find if Path Exists in Graph[Solved]
- 200. Number of Islands[Solved]
- 695. Max Area of Island[Solved]
- 994. Rotting Oranges[Solved]
- 130. Surrounded Regions[Solved]
- 207. Course Schedule[Solved]
- 210. Course Schedule II[Solved]
- Implement Shortest Path Dijkstra's Algorithm[Solved]
- Implement Disjoint Set Union (DSU) Algorithm[Solved]
- Implement Kruskal's Algorithm to find MST[Solved]
- Implement Prim's Algorithm to find MST[Solved]
- 797. All Paths From Source to Target[Unsolved]
- 417. Pacific Atlantic Water Flow[Unsolved]
- 1905. Count Sub Islands[Unsolved]
- 1162. As Far from Land as Possible[Unsolved]
- 338. Counting Bits
- 191. Number of 1 Bits
- 231. Power of Two
- 342. Power of Four
- 389. Find the Difference
- 405. Convert a Number to Hexadecimal
- 190. Reverse Bits
- 461. Hamming Distance
- 476. Number Complement
- 693. Binary Number with Alternating Bits
- 762. Prime Number of Set Bits in Binary Representation
- 868. Binary Gap
- 3158. Find the XOR of Numbers Which Appear Twice
- 1018. Binary Prefix Divisible By 5
- 3226. Number of Bit Changes to Make Two Integers Equal
- 1486. XOR Operation in an Array
- 1342. Number of Steps to Reduce a Number to Zero
- 1356. Sort Integers by The Number of 1 Bits
- 1009. Complement of Base 10 Integer
- 2980. Check if Bitwise OR Has Trailing Zeros
- 371. Sum of Two Integers
- 477. Total Hamming Distance
- 136. Single Number
- 137. Single Number II
- 1684. Count the Number of Consistent Strings
- 3011. Find if Array Can Be Sorted
- 3095. Shortest Subarray With OR at Least K I
- 832. Flipping an Image
- 645. Set Mismatch
- 2932. Maximum Strong Pair XOR I
- 3304. Find the K-th Character in String Game I
- 318. Maximum Product of Word Lengths
- 1720. Decode XORed Array
- 2220. Minimum Bit Flips to Convert Number
- 2595. Number of Even and Odd Bits
- 2032. Two Out of Three
- 2351. First Letter to Appear Twice
- 2506. Count Pairs Of Similar Strings
- 2859. Sum of Values at Indices With K Set Bits
- 2869. Minimum Operations to Collect Elements
- 2917. Find the K-or of an Array
- 2206. Divide Array Into Equal Pairs
- 3314. Construct the Minimum Bitwise Array I
- 1763. Longest Nice Substring
- Prime Number
- 204. Count Primes
- 258. Add Digits
- 263. Ugly Number
- 504. Base 7
- 202. Happy Number
- 507. Perfect Number
- 118. Pascal's Triangle
- 2520. Count the Digits That Divide a Number
- 326. Power of Three
- 415. Add Strings
- 168. Excel Sheet Column Title
- 171. Excel Sheet Column Number
- 1952. Three Divisors
- 2413. Smallest Even Multiple
- 2748. Number of Beautiful Pairs
- 2427. Number of Common Factors
- 1979. Find Greatest Common Divisor of Array
- 914. X of a Kind in a Deck of Cards
- 866. Prime Palindrome[Unsolved]
- 14. Longest Common Prefix
- 3280. Convert Date to Binary
- 58. Length of Last Word
- 709. To Lower Case
- 28. Find the Index of the First Occurrence in a String
- 796. Rotate String
- 520. Detect Capital
- 125. Valid Palindrome
- 392. Is Subsequence
- 917. Reverse Only Letters
- 1154. Day of the Year
- 2942. Find Words Containing Character
- 680. Valid Palindrome II
- 1446. Consecutive Characters
- 551. Student Attendance Record I
- 821. Shortest Distance to a Character
- 1528. Shuffle String
- 1071. Greatest Common Divisor of Strings
- 1903. Largest Odd Number in String
- 2264. Largest 3-Same-Digit Number in String
- 434. Number of Segments in a String
- 459. Repeated Substring Pattern
- 819. Most Common Word
- 925. Long Pressed Name
- 1002. Find Common Characters
- 1221. Split a String in Balanced Strings
- 1360. Number of Days Between Two Dates
- 1624. Largest Substring Between Two Equal Characters
- 1408. String Matching in an Array
- 824. Goat Latin
- 541. Reverse String II
- 1417. Reformat The String[VVI]
- 1455. Check If a Word Occurs As a Prefix of Any Word in a Sentence
- 2255. Count Prefixes of a Given String
- 1961. Check If String Is a Prefix of Array
- 2185. Counting Words With a Given Prefix
- 804. Unique Morse Code Words
- 2287. Rearrange Characters to Make Target String[VVI]
- 2278. Percentage of Letter in String
- 1704. Determine if String Halves Are Alike
- 1790. Check if One String Swap Can Make Strings Equal
- 1859. Sorting the Sentence[VVI]
- 884. Uncommon Words from Two Sentences
- StringCompression