Author: devangini123

Problem Statement: A path in a binary tree is a sequence of nodes where each pair of adjacent nodes in the sequence has an edge connecting them. A node can only appear in the sequence at most once. Note that the path does not need to pass through the root. The path sum of a path is the sum of the node’s values in the path. Given the root of a binary tree, return the maximum path sum of any non-empty path. Examples: Example 1: Input: root = [1,2,3] Output: 6 Explanation: The optimal path is 2 -> 1 ->…

Problem Statement: You are given a perfect binary tree where all leaves are on the same level, and every parent has two children. The binary tree has the following definition: struct Node { int val; Node *left; Node *right; Node *next; } Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL. Initially, all next pointers are set to NULL. Examples: Example 1: Input: root = [1,2,3,4,5,6,7] Output: [1,#,2,3,#,4,5,6,7,#] Explanation: Given the above perfect binary tree (Figure A), your function should populate each next…

Problem Statement: Given the roots of two binary trees root and subRoot, return true if there is a subtree of root with the same structure and node values of subRoot and false otherwise. A subtree of a binary tree tree is a tree that consists of a node in tree and all of this node’s descendants. The tree tree could also be considered as a subtree of itself. Examples: Example 1: Input: root = [3,4,5,1,2], subRoot = [4,1,2] Output: true Example 2: Input: root = [3,4,5,1,2,null,null,null,null,0], subRoot = [4,1,2] Output: false Constraints: The number of nodes in the root tree…

Problem Statement: Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes p and q as the lowest node in T that has both p and q as descendants (where we allow a node to be a descendant of itself).” Examples: Example 1: Input: root = [3,5,1,6,2,0,8,null,null,7,4], p = 5, q = 1 Output: 3 Explanation: The LCA of nodes 5 and 1 is 3. Example 2: Input: root = [3,5,1,6,2,0,8,null,null,7,4], p = 5, q =…

Problem Statement: Given the root of a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bottom. Examples: Example 1: Input: root = [1,2,3,null,5,null,4] Output: [1,3,4] Explanation: Example 2: Input: root = [1,2,3,4,null,null,null,5] Output: [1,3,4,5] Explanation: Example 3: Input: root = [1,null,3] Output: [1,3] Example 4: Input: root = [] Output: [] Constraints: The number of nodes in the tree is in the range [0, 100]. -100 right) q.push(curr->right); if (curr->left) q.push(curr->left); } } return ans; } typedef struct TreeNode { int val; struct TreeNode…

Problem Statement: Given a binary tree root, a node X in the tree is named good if in the path from root to X there are no nodes with a value greater than X. Return the number of good nodes in the binary tree. Examples: Example 1: Input: root = [3,1,4,3,null,1,5] Output: 4 Explanation: Nodes in blue are good. Root Node (3) is always a good node. Node 4 -> (3,4) is the maximum value in the path starting from the root. Node 5 -> (3,4,5) is the maximum value in the path Node 3 -> (3,1,3) is the maximum…

Problem Statement: Given the root of a binary tree, return the zigzag level order traversal of its nodes’ values. (i.e., from left to right, then right to left for the next level and alternate between). Examples: Example 1: Input: root = [3,9,20,null,null,15,7] Output: [[3],[20,9],[15,7]] Example 2: Input: root = [1] Output: [[1]] Example 3: Input: root = [] Output: [] Constraints: The number of nodes in the tree is in the range [0, 2000]. -100 left) q.push(node->left); if (node->right) q.push(node->right); } ans.push_back(level); leftToRight = !leftToRight; } return ans; } void zigzagLevelOrder(TreeNode* root) { if (root == NULL) return; Queue* q…

Problem Statement: Given the root of a binary tree, return the length of the diameter of the tree. The diameter of a binary tree is the length of the longest path between any two nodes in a tree. This path may or may not pass through the root. The length of a path between two nodes is represented by the number of edges between them. Examples: Example 1: Input: root = [1,2,3,4,5] Output: 3 Explanation: 3 is the length of the path [4,2,1,3] or [5,2,1,3]. Example 2: Input: root = [1,2] Output: 1 Constraints: The number of nodes in the…

Problem Statement: Given a binary tree, determine if it is height-balanced. Examples: Example 1: Input: root = [3,9,20,null,null,15,7] Output: true Example 2: Input: root = [1,2,2,3,3,null,null,4,4] Output: false Example 3: Input: root = [] Output: true Constraints: The number of nodes in the tree is in the range [0, 100]. -104 1){ ans = ans && false; } return 1 + Math.max(leftHeight, rightHeight); } calculateHeight(root); return ans; }; class Solution: def isBalanced(self, root): self.ans = True def calculateHeight(node): if not node: return 0 left = calculateHeight(node.left) right = calculateHeight(node.right) if abs(left – right) > 1: self.ans = False return 1…

Problem Statement: Given the roots of two binary trees p and q, write a function to check if they are the same or not. Two binary trees are considered the same if they are structurally identical, and the nodes have the same value. Examples: Example 1: Input: p = [1,2,3], q = [1,2,3] Output: true Example 2: Input: p = [1,2], q = [1,null,2] Output: false Example 3: Input: p = [1,2,1], q = [1,1,2] Output: false Constraints: The number of nodes in the tree is in the range [0, 100]. -104 val && isSameTree(p->left, q->left) && isSameTree(p->right, q->right); }…