111. Minimum Depth of Binary Tree

问题描述：

Given a binary tree, find its minimum depth.

The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.

即这道题要求找出二叉树中根节点到最近一个叶节点的距离。

问题分析：

由于题目给出的树是一颗二叉树，那么整个问题就简单化了。我们只需要思考以下几种情况就好：①这个树为空，那么距离当然为0；②这个树只有一个根节点，那么距离为1；③这个树存在叶节点。第三种情况相对复杂一些，我们把情况细化，可以分解为，一个父节点到叶节点的最小距离，可以由其子节点到叶节点的最小距离得到。其中，父节点到叶节点的最小距离，为其左节点到叶节点的最小距离与其右节点到叶节点的最小距离直接的比较，取较小值加1.

那么，这道题可以用递归的方式求解。给出递归的终结条件（即该节点为空或者该节点为叶节点），按照第三种情况的关系实现即可。

代码：

 1 /**
 2  * Definition for a binary tree node.
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10  #include <queue>
11 class Solution {
12 public:
13     int minDepth(TreeNode* root) {
14        if(!root) return 0;
15        if(!root->left && !root->right) return 1;
16        int left = minDepth(root->left);
17        int right = minDepth(root->right);
18        if(left == 0)
19        return right + 1;
20        if(right == 0)
21        return left + 1;
22        return left<right?left+1:right+1;
23     }
24 };

转载于:https://www.cnblogs.com/MT-ComputerVision/p/6985854.html

111. Minimum Depth of Binary Tree相关推荐

LeetCode： 111. Minimum Depth of Binary Tree
题目 Given a binary tree, determine if it is height-balanced. For this problem, a height-balanced bina ...
LeetCode 111. Minimum Depth of Binary Tree
原题 Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the s ...
leetcode python3 简单题111. Minimum Depth of Binary Tree
1.编辑器我使用的是win10+vscode+leetcode+python3 环境配置参见我的博客: 链接 2.第一百一十一题 (1)题目英文: Given a binary tree, fin ...
LeetCode 111. Minimum Depth of Binary Tree （二叉树最小的深度）
Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shor ...
111. Minimum Depth of Binary Tree
1.问题描述 Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along t ...
111. Minimum Depth of Binary Tree 二叉树的最小深度
给定一个二叉树,找出其最小深度. 最小深度是从根节点到最近叶子节点的最短路径上的节点数量. 说明: 叶子节点是指没有子节点的节点. 示例: 给定二叉树 [3,9,20,null,null,15,7], ...
【LeetCode】Minimum Depth of Binary Tree 二叉树的最小深度 java
[LeetCode]Minimum Depth of Binary Tree Given a binary tree, find its minimum depth. The minimum dept ...
LeetCode 111. Minimum Depth of Binary Tree--Java, Python解法--二叉树最小高度--迭代，递归
题目地址:Minimum Depth of Binary Tree - LeetCode Given a binary tree, find its minimum depth. The minimu ...
LeetCode:Minimum Depth of Binary Tree,Maximum Depth of Binary Tree
LeetCode:Minimum Depth of Binary Tree Given a binary tree, find its minimum depth. The minimum depth ...
leetcode - Minimum Depth of Binary Tree
题目:Minimum Depth of Binary Tree Given a binary tree, find its minimum depth. The minimum depth is th ...

111. Minimum Depth of Binary Tree

111. Minimum Depth of Binary Tree相关推荐

最新文章

热门文章