Featured Lists Top 20 Problems on Dynamic programming Top 10 Problems on Backtracking Top 20 Problems on Graph Top 25 Problems on Trees Top 10 Problems on Bits Manipulation Top 15 Problems in LinkedList All Problems # Status Problem video Level Completes Likes 123 Colorful Numbers Hard % 3 541 Find an extra element in two almost similar arrays Beginner % 5 540 find the Arithmetic Progression sequence Beginner % 3 539 Find the Nth-term in a given arithmetic progression Beginner % 1 536 Efficiently Rank Elements in a Given Array Beginner % 3 525 Find the number of pairs with odd XOR Beginner % 2 527 In a number, add digits until it becomes a single digit Beginner % 1 516 Count similar words in a given array Beginner % 1 58 Generate All String Permutations Hard % 0 549 Dynamic Programming - Minimum Cost for Climbing Stairs Medium % 0 545 Maximizing Contiguous Ones with a Single Flip in a Binary Array Medium % 3 535 Find Three Consecutive Odd Numbers in an array Beginner % 2 531 Convert a Decimal number to its binary representation Beginner % 1 530 Find Maximum Consecutive Ones in an Array Beginner % 0 496 Minimum number of times String A is repeated to such that B is substring of A Beginner % 1 551 Reverse a linked list using stack Medium % 0 548 Minimum Number of Halls Required for Lecture Scheduling Hard % 1 547 Maximum Contiguous ones after one deletion Medium % 2 513 Sort 0, 1, 2 in an array - Part 1 Beginner % 1 493 Maximum meetings in one room Medium % 0 470 Find if any two intervals overlap in given intervals Medium % 0 354 Valid Multiple Parentheses Medium % 1 267 Graph – Depth First Search using Recursion Beginner % 1 257 Graph – Depth First Traversal Medium % 2 223 Stock Single Sell Problem - Dynamic Programming - O(n) Medium % 2 177 Tree Traversals Beginner % 1 151 Breadth-First Search/Traversal in a Binary Tree Beginner % 0 145 Dynamic Programming - Minimum Coin Change Problem Medium % 1 144 Introduction To Dynamic Programming - Fibonacci Series Beginner % 1 115 Graph Representation - Adjacency Matrix and Adjacency List Beginner % 2 41 Sorted Array to Binary Search Tree of Minimal Height Medium % 1 36 Find the Maximum Depth OR Height of a Binary Tree Beginner % 1 537 Departure and Destination Cities in a given itinerary Beginner % 2 534 Convert to Non-decreasing Array with one change Beginner % 1 529 Duplicate even elements in an array Beginner % 1 Colorful Numbers Find an extra element in two almost similar arrays find the Arithmetic Progression sequence Find the Nth-term in a given arithmetic progression Efficiently Rank Elements in a Given Array Find the number of pairs with odd XOR In a number, add digits until it becomes a single digit Count similar words in a given array Generate All String Permutations Dynamic Programming - Minimum Cost for Climbing Stairs Maximizing Contiguous Ones with a Single Flip in a Binary Array Find Three Consecutive Odd Numbers in an array Convert a Decimal number to its binary representation Find Maximum Consecutive Ones in an Array Minimum number of times String A is repeated to such that B is substring of A Reverse a linked list using stack Minimum Number of Halls Required for Lecture Scheduling Maximum Contiguous ones after one deletion Sort 0, 1, 2 in an array - Part 1 Maximum meetings in one room Find if any two intervals overlap in given intervals Valid Multiple Parentheses Graph – Depth First Search using Recursion Graph – Depth First Traversal Stock Single Sell Problem - Dynamic Programming - O(n) Tree Traversals Breadth-First Search/Traversal in a Binary Tree Dynamic Programming - Minimum Coin Change Problem Introduction To Dynamic Programming - Fibonacci Series Graph Representation - Adjacency Matrix and Adjacency List Sorted Array to Binary Search Tree of Minimal Height Find the Maximum Depth OR Height of a Binary Tree Departure and Destination Cities in a given itinerary Convert to Non-decreasing Array with one change Duplicate even elements in an array 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16