# Status Problem Level Completes Likes 71 Backtracking - N Queens Problem Hard % 0 72 Backtracking - Rat In A Maze Puzzle Hard % 0 73 Backtracking - SUDOKU Solver Hard % 0 74 Dynamic Programming - Stairs Climbing Puzzle Beginner % 1 75 Dynamic Programming - Minimum Coin Change Problem Medium % 1 76 Merge K Sorted Arrays Hard % 0 77 Find a Number occurring odd number of times in a Given array Beginner % 1 78 Diameter Of a Binary Tree Hard % 1 79 Magic Index - Find Index In Sorted Array Such That A[i] = i. Beginner % 0 80 Find numbers that are palindrome in the decimal and octal Representations Beginner % 0 81 Find All the Well Ordered Permutations of a Given String. Medium % 0 82 Find the Increasing Triplet Sub-sequence in an array Medium % 0 83 Colorful Numbers Hard % 0 84 Print All the Subsets of a Given Set (Power Set) Hard % 1 85 Print All Possible Valid Combinations Of Parenthesis of Given 'N' Hard % 1 86 Implement Queue Using Stacks Medium % 0 87 Merge Sort in a Linked list Medium % 0 88 Construct a binary tree from given Inorder and Level Order Traversal Hard % 0 89 Construct Binary Search Tree from a given Preorder Traversal Using Stack (Without Recursion) Hard % 0 90 Construct Binary Search Tree from a given Preorder Traversal using Recursion Hard % 0 91 Given an array arrA[], find the maximum j – i such that arr[j] > arr[i]. Medium % 0 92 Find All Elements in an Array which appears more than N/K times, N is Array Size and k is a Number. Hard % 0 93 Print All The Nodes Which are X distance from the Given Node Hard % 0 94 Find the Distance between Two Nodes of a Binary Tree. Hard % 0 95 Lowest Common Ancestor in a Binary Tree (Not Binary Search Tree). Hard % 0 96 Lowest Common Ancestor in a Binary Search Tree. Medium % 0 97 Make a Binary Tree from Given Inorder and Preorder Traveral. Hard % 0 98 Convert a Sorted Doubly Linked List to Balanced BST. Medium % 1 99 Find the number of occurrences of a number in a given sorted array. Medium % 0 100 Inorder Successor in Binary Tree Medium % 0 101 Inorder Successor in Binary Search Tree without Using Parent link Hard % 0 102 Inorder Successor in Binary Search Tree Using Parent link Hard % 0 103 In a Binary Tree, Create Linked Lists of all the nodes at each depth. Hard % 0 104 Level Order Traversal, Print each level in separate line. Medium % 0 105 Rearrange Positive and Negative Numbers of Array On Each Side in O(nlogn) Hard % 0 Backtracking - N Queens Problem Backtracking - Rat In A Maze Puzzle Backtracking - SUDOKU Solver Dynamic Programming - Stairs Climbing Puzzle Dynamic Programming - Minimum Coin Change Problem Merge K Sorted Arrays Find a Number occurring odd number of times in a Given array Diameter Of a Binary Tree Magic Index - Find Index In Sorted Array Such That A[i] = i. Find numbers that are palindrome in the decimal and octal Representations Find All the Well Ordered Permutations of a Given String. Find the Increasing Triplet Sub-sequence in an array Colorful Numbers Print All the Subsets of a Given Set (Power Set) Print All Possible Valid Combinations Of Parenthesis of Given 'N' Implement Queue Using Stacks Merge Sort in a Linked list Construct a binary tree from given Inorder and Level Order Traversal Construct Binary Search Tree from a given Preorder Traversal Using Stack (Without Recursion) Construct Binary Search Tree from a given Preorder Traversal using Recursion Given an array arrA[], find the maximum j – i such that arr[j] > arr[i]. Find All Elements in an Array which appears more than N/K times, N is Array Size and k is a Number. Print All The Nodes Which are X distance from the Given Node Find the Distance between Two Nodes of a Binary Tree. Lowest Common Ancestor in a Binary Tree (Not Binary Search Tree). Lowest Common Ancestor in a Binary Search Tree. Make a Binary Tree from Given Inorder and Preorder Traveral. Convert a Sorted Doubly Linked List to Balanced BST. Find the number of occurrences of a number in a given sorted array. Inorder Successor in Binary Tree Inorder Successor in Binary Search Tree without Using Parent link Inorder Successor in Binary Search Tree Using Parent link In a Binary Tree, Create Linked Lists of all the nodes at each depth. Level Order Traversal, Print each level in separate line. Rearrange Positive and Negative Numbers of Array On Each Side in O(nlogn) 1 2 3 4
