劍指offer-二叉樹的深度(python和c++）

題目描述

輸入一棵二叉樹，求該樹的深度。從根結點到葉結點依次經過的結點（含根、葉結點）形成樹的一條路徑，最長路徑的長度爲樹的深度。

思路：層次遍歷，直接遍歷每一層，左右節點不爲空d就加1。

python

# -*- coding:utf-8 -*-
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
class Solution:
    def TreeDepth(self, pRoot):
        # write code here
        if not pRoot:
            return 0
        a = [pRoot]
        d = 0
        while a :
            b = []
            for node in a:
                if node.left:
                    b.append(node.left)
                if node.right:
                    b.append(node.right)
            a = b
            d = d + 1
        return d
    

c++的代碼實現給遞歸方法

c++

/*
struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
    TreeNode(int x) :
            val(x), left(NULL), right(NULL) {
    }
};*/
class Solution {
public:
    int TreeDepth(TreeNode* pRoot)
    {
        if(pRoot==NULL)
            return 0;
        return max(TreeDepth(pRoot->left),TreeDepth(pRoot->right))+1;
    }
};