[LeetCode 104] Maximum Depth of Binary Tree

Problem

Given the root of a binary tree, return its maximum depth.

A binary tree’s maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

Example 1:

Input: root = [3,9,20,null,null,15,7]
Output: 3

Example 2:

Input: root = [1,null,2]
Output: 2

Constraints:

- The number of nodes in the tree is in the range [0, 104].
- -100 <= Node.val <= 100

TypeScript

/**
 * Definition for a binary tree node.
 * class TreeNode {
 *     val: number
 *     left: TreeNode | null
 *     right: TreeNode | null
 *     constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
 *         this.val = (val===undefined ? 0 : val)
 *         this.left = (left===undefined ? null : left)
 *         this.right = (right===undefined ? null : right)
 *     }
 * }
 */

function maxDepth(root: TreeNode | null): number {
    
    const depth = (node: TreeNode): number => {
        if(node === null) return 0;
        
        const leftDepth: number = 1 + depth(node.left);
        const rightDepth: number = 1 + depth(node.right);
        
        return Math.max(leftDepth, rightDepth)
    }
    
    return depth(root);
};

Reference

https://leetcode.com/problems/maximum-depth-of-binary-tree/

Tags

[LeetCode 104] Maximum Depth of Binary Tree

Problem

Example 1:

Example 2:

Constraints:

TypeScript

Reference