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 118 Print All Combinations of subset of size K from Given Array Hard % 0 106 Reverse a Doubly-Linked List (In-place Algorithm) Medium % 0 105 Swapping Nodes in a Linked List (Kth Position) Medium % 0 104 Print the Bottom View of a Binary Tree Medium % 0 103 Delete X Nodes After Y Nodes In a Linked List Beginner % 0 101 Merge a Linked list into another Linked List at Alternate Positions Medium % 0 99 Construct a binary tree from given Inorder and Level Order Traversal Hard % 0 98 Construct Binary Search Tree from a given Preorder Traversal Using Stack (Without Recursion) Hard % 0 96 Print The Top View of a Binary Tree Medium % 0 95 Construct a Binary Tree from Given Inorder and Depth-First-Search Hard % 0 93 Inorder Predecessor and Successor in Binary Search Tree Hard % 0 88 Rearrange Array: Positive and Negative Elements Alternating Hard % 0 84 Elements in an Array Occurring More Than N/K Times Hard % 0 83 Find Element in Rotated Sorted Array Medium % 0 80 Find Nodes at Distance X from Root in a Tree Medium % 0 79 Calculate Distance Between Nodes in a Binary Tree Hard % 0 78 Root-to-Node Distance in Binary Tree: How to Find Medium % 0 77 Construct a binary tree from given Inorder and Postorder Traversal Hard % 0 76 Calculate Vertical Sum in Binary Tree Medium % 0 75 Print the Binary Tree in Vertical Order Path Medium % 0 72 Make a Binary Tree from Given Inorder and Preorder Traversal Hard % 0 71 Given a binary tree, find out the maximum sum of value from root to each leaf Medium % 0 70 Reversing Alternate Levels in a Binary Tree Medium % 0 64 Print Left View of binary tree Medium % 0 60 Determine if Two BSTs are Identical Beginner % 0 59 Print All Root-to-Leaf Paths in a Binary Tree Medium % 0 53 Count occurrences of a number in a sorted array Medium % 0 51 Print Binary Tree Nodes in Zigzag Order: Spiral Traversal Pattern Hard % 0 50 Find the first repeated element in an array by its index Medium % 0 43 Inorder Successor in Binary Search Tree without Using Parent link Hard % 0 42 Inorder Successor in Binary Search Tree Using Parent link Hard % 0 40 In a Binary Tree, Create Linked Lists of all the nodes at each depth Hard % 0 39 Level Order Traversal, Print each level in separate line Medium % 0 32 Binary Search Tree (BST) Complete Implementation. Beginner % 0 30 Swap Every Kth Node in a LinkedList Medium % 0 Print All Combinations of subset of size K from Given Array Reverse a Doubly-Linked List (In-place Algorithm) Swapping Nodes in a Linked List (Kth Position) Print the Bottom View of a Binary Tree Delete X Nodes After Y Nodes In a Linked List Merge a Linked list into another Linked List at Alternate Positions Construct a binary tree from given Inorder and Level Order Traversal Construct Binary Search Tree from a given Preorder Traversal Using Stack (Without Recursion) Print The Top View of a Binary Tree Construct a Binary Tree from Given Inorder and Depth-First-Search Inorder Predecessor and Successor in Binary Search Tree Rearrange Array: Positive and Negative Elements Alternating Elements in an Array Occurring More Than N/K Times Find Element in Rotated Sorted Array Find Nodes at Distance X from Root in a Tree Calculate Distance Between Nodes in a Binary Tree Root-to-Node Distance in Binary Tree: How to Find Construct a binary tree from given Inorder and Postorder Traversal Calculate Vertical Sum in Binary Tree Print the Binary Tree in Vertical Order Path Make a Binary Tree from Given Inorder and Preorder Traversal Given a binary tree, find out the maximum sum of value from root to each leaf Reversing Alternate Levels in a Binary Tree Print Left View of binary tree Determine if Two BSTs are Identical Print All Root-to-Leaf Paths in a Binary Tree Count occurrences of a number in a sorted array Print Binary Tree Nodes in Zigzag Order: Spiral Traversal Pattern Find the first repeated element in an array by its index 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 Binary Search Tree (BST) Complete Implementation. Swap Every Kth Node in a LinkedList 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16