# Status Problem video Level Completes Likes 162 Dynamic Programming - Subset Sum Problem Hard % 0 161 The Word Break Problem Hard % 0 159 Solve the Knight's Tour with Backtracking Hard % 0 158 Backtracking - Search a Word In a Matrix Hard % 0 157 Backtracking - N Queens Problem - Better Solution Hard % 0 156 Backtracking - N Queens Problem Hard % 0 149 Backtracking - Rat In A Maze Puzzle Hard % 0 148 Solve Sudoku Puzzles with Backtracking Hard % 0 143 Merge K Sorted Arrays Hard % 0 137 Populate Next Right Pointers in Each Node Hard % 0 134 Diameter Of a Binary Tree Hard % 1 129 Binary Min-Max Heap Implementation Hard % 0 123 Colorful Numbers Hard % 3 121 Print All the Subsets of a Given Set (Power Set) Hard % 1 118 Print All Combinations of subset of size K from Given Array Hard % 0 100 AVL Tree - Insertion Hard % 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 97 Construct Binary Search Tree from a given Preorder Traversal using Recursion Hard % 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 82 Find Nodes at Distance X from a Given Node in a Tree Hard % 0 79 Calculate Distance Between Nodes in a Binary Tree Hard % 0 77 Construct a binary tree from given Inorder and Postorder Traversal Hard % 0 74 Lowest Common Ancestor in a Binary Tree (Not Binary Search Tree). Hard % 0 72 Make a Binary Tree from Given Inorder and Preorder Traversal Hard % 0 58 Generate All String Permutations Hard % 0 51 Print Binary Tree Nodes in Zigzag Order: Spiral Traversal Pattern Hard % 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 15 Efficiently Rearrange Positive and Negative Numbers in Array on Each Side Hard % 0 Dynamic Programming - Subset Sum Problem The Word Break Problem Solve the Knight's Tour with Backtracking Backtracking - Search a Word In a Matrix Backtracking - N Queens Problem - Better Solution Backtracking - N Queens Problem Backtracking - Rat In A Maze Puzzle Solve Sudoku Puzzles with Backtracking Merge K Sorted Arrays Populate Next Right Pointers in Each Node Diameter Of a Binary Tree Binary Min-Max Heap Implementation Colorful Numbers Print All the Subsets of a Given Set (Power Set) Print All Combinations of subset of size K from Given Array AVL Tree - Insertion 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 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 Nodes at Distance X from a Given Node in a Tree Calculate Distance Between Nodes in a Binary Tree Construct a binary tree from given Inorder and Postorder Traversal Lowest Common Ancestor in a Binary Tree (Not Binary Search Tree). Make a Binary Tree from Given Inorder and Preorder Traversal Generate All String Permutations Print Binary Tree Nodes in Zigzag Order: Spiral Traversal Pattern 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 Efficiently Rearrange Positive and Negative Numbers in Array on Each Side 1 2 3