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 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 74 Lowest Common Ancestor in a Binary Tree (Not Binary Search Tree). Hard % 0 73 Lowest Common Ancestor in a Binary Search Tree. 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 68 Transforming a Binary Tree into its Mirror Image Beginner % 0 67 Printing Nodes without Siblings in a Binary Tree Beginner % 0 65 Given a binary tree, Find the Maximum Path Sum between Any Two Leaves Medium % 0 64 Print Left View of binary tree Medium % 0 63 Print Right View of Binary Tree Medium % 0 62 In a Binary Tree, Check if Two nodes has the same parent or are siblings Medium % 0 61 Determine If Two Nodes are Cousins Medium % 0 60 Determine if Two BSTs are Identical Beginner % 0 59 Print All Root-to-Leaf Paths in a Binary Tree Medium % 0 58 Generate All String Permutations Hard % 0 57 Sort an Array According to the Order Defined by Another Array Medium % 0 56 Sort an Array - odd numbers appear first in ascending order followed by the even numbers in descending order. Medium % 0 55 Print Nodes Between Two Levels in Binary Tree Medium % 0 54 Maximum Width of a Binary Tree Medium % 0 53 Count occurrences of a number in a sorted array Medium % 0 52 Find Common Numbers in Three Sorted Arrays Beginner % 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 49 Find the Unreachable Minimum in Array Subsets Medium % 0 47 Find the Size of the Binary Tree Beginner % 0 46 Check if One Binary Tree is a Subtree of Another Medium % 0 45 Print a path from Root to Node in Binary Tree Medium % 0 44 Inorder Successor in Binary Tree 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 Construct a binary tree from given Inorder and Postorder Traversal Calculate Vertical Sum in Binary Tree Print the Binary Tree in Vertical Order Path 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 Traversal Given a binary tree, find out the maximum sum of value from root to each leaf Reversing Alternate Levels in a Binary Tree Transforming a Binary Tree into its Mirror Image Printing Nodes without Siblings in a Binary Tree Given a binary tree, Find the Maximum Path Sum between Any Two Leaves Print Left View of binary tree Print Right View of Binary Tree In a Binary Tree, Check if Two nodes has the same parent or are siblings Determine If Two Nodes are Cousins Determine if Two BSTs are Identical Print All Root-to-Leaf Paths in a Binary Tree Generate All String Permutations Sort an Array According to the Order Defined by Another Array Sort an Array - odd numbers appear first in ascending order followed by the even numbers in descending order. Print Nodes Between Two Levels in Binary Tree Maximum Width of a Binary Tree Count occurrences of a number in a sorted array Find Common Numbers in Three Sorted Arrays Print Binary Tree Nodes in Zigzag Order: Spiral Traversal Pattern Find the first repeated element in an array by its index Find the Unreachable Minimum in Array Subsets Find the Size of the Binary Tree Check if One Binary Tree is a Subtree of Another Print a path from Root to Node in Binary Tree 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 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16