[剑指offer]二叉树的深度

题目描述

输入一棵二叉树，求该树的深度。从根结点到叶结点依次经过的结点（含根、叶结点）形成树的一条路径，最长路径的长度为树的深度。

 

 

 

题目链接：

https://www.nowcoder.com/practice/435fb86331474282a3499955f0a41e8b?tpId=13&tqId=11191&rp=2&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking

 

 

 

package com.sunshine.OFFER66_SECOND;

public class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;

    TreeNode(int x) {
        val = x;
    }
}

 

 

package com.sunshine.OFFER66_SECOND;

import org.junit.Test;

public class A38_TreeDepth {

    @Test
    public void test() {
        TreeNode n1 = new TreeNode(1);
        TreeNode n2 = new TreeNode(2);
        TreeNode n3 = new TreeNode(3);
        TreeNode n4 = new TreeNode(4);
        TreeNode n5 = new TreeNode(5);
        n1.left = n2;
        n2.right = n3;
        n3.left = n4;
        n3.right = n5;
        int i = TreeDepth(n1);
        System.out.println(i);
    }

    public int TreeDepth(TreeNode root) {
        if (root == null) {
            return 0;
        }
        int leftDepth = TreeDepth(root.left);
        int rightDepth = TreeDepth(root.right);
        return (leftDepth > rightDepth ? leftDepth : rightDepth) + 1;
    }
}