/** * Definition for a binary tree node. * type TreeNode struct { * Val int * Left *TreeNode * Right *TreeNode * } */ funcmaxDepth(root *TreeNode)int {
var res int if root == nil { return res }
left := maxDepth(root.Left) right := maxDepth(root.Right)
if left > right { return left + 1//根节点也算一层 } else { return right + 1 }