104-maximum-depth-of-binary-tree

104. Maximum Depth of Binary Tree (Easy) (https://leetcode.com/problems/maximum-depth-of-binary-tree/)

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. Constraints: - The number of nodes in the tree is in the range [0, 10

• -100 <= Node.val <= 100

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 {
  if (root === null) {
    return 0
  }
 
  return 1 + Math.max(maxDepth(root.left), maxDepth(root.right))
}
 
// Local check:
const root = new TreeNode(
  3,
  new TreeNode(9),
  new TreeNode(20, new TreeNode(15), new TreeNode(7)),
)
console.log(maxDepth(root)) // 3
 
const root2 = new TreeNode(1, null, new TreeNode(2))
console.log(maxDepth(root2)) // 2

Example 1:
 
    Input: root = [3,9,20,null,null,15,7]
    Output: 3
 
  Example 2:
 
    Input: root = [1,null,2]
    Output: 2

binary-tree