package top100liked

// https://leetcode.cn/problems/diameter-of-binary-tree/description/?envType=study-plan-v2&envId=top-100-liked

type TreeNode struct {
	Val   int
	Left  *TreeNode
	Right *TreeNode
}

func diameterOfBinaryTree(root *TreeNode) int {
	maxDiameter := 0

	var depth func(node *TreeNode) int
	depth = func(node *TreeNode) int {
		if node == nil {
			return 0
		}
		left := depth(node.Left)
		right := depth(node.Right)
		maxDiameter = max(maxDiameter, left+right)
		return max(left, right) + 1
	}

	depth(root)
	return maxDiameter
}