题解 | #二叉树的最大深度#

package main
import . "nc_tools"
/*
 * type TreeNode struct {
 *   Val int
 *   Left *TreeNode
 *   Right *TreeNode
 * }
 */

/**
  * 
  * @param root TreeNode类 
  * @return int整型
*/
func maxDepth( root *TreeNode ) int {
    // write code here
    var dfs func(root *TreeNode) int
    dfs = func(root *TreeNode) int {
        if root == nil {
            return 0
        }
        return max(dfs(root.Left), dfs(root.Right)) + 1
    }
    return dfs(root)
}

func max (a, b int) int {
    if a > b {
        return a
    }
    return b
}