题目描述: 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. 解法一:非递归方式,使用层序遍历的方法,借助队列,思想比较简单. int minDepth(TreeNode* root) { ; if(!root) return r…

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. 题目标题:Tree 这道题目给了我们一个二叉树,让我们找到它最小的深度,注意这里的最小深度是指root 到一个 leaf node. 举个例子: 1 /   2 / 3 这种情况,…

[Leetcode] Maximum and Minimum Depth of Binary Tree 二叉树的最小最大深度 (最小有3种解法) 描述 解析 递归深度优先搜索 当求最大深度时,我们只要在左右子树中取较大的就行了. 然而最小深度时,如果左右子树中有一个为空会返回0,这时我们是不能算做有效深度的. 所以分成了三种情况,左子树为空,右子树为空,左右子树都不为空.当然,如果左右子树都为空的话,就会返回1. 广度优先搜索(类似层序遍历的思想) 递归解法本质是深度优先搜索,但因为我们是求最小…

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. 给一个二叉树,找出它的最小深度.最小深度是从根节点向下到最近的叶节点的最短路径,就是最短路径的节点个数. 解法1:DFS 解法2: BFS Java: DFS, Time Comp…

111. 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], 3 / \ 9 20 / \ 15 7 返回它的最小深度 2. class Solution { public int minDepth(TreeNode root) { if (root == null) { return 0; } // null节点不参与比较 if…

problem description: 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. problem analysis: 第一步,设计演算法:遍历一棵树的方法有两种,BFS and DFS,思考了下,BFS是一圈一圈的扩张出…

找出最短的从叶子到根的路径长 可以回忆Maximum Depth of Binary Tree的写法,只不过在!root,我把它改成了10000000,还有max函数改成了min函数,最后的值如果是10000000,毫无疑问这棵树肯定为空,因此在最后有(d>=1000000)?0:d; /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *righ…

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.  求树的最低高度. 没什么技巧性,用队列,遇到叶子结点的时候返回结果.   /** * Definition for a binary tree node. * public cl…

题目描述: 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. 解题思路: 递归. 代码描述: /** * Definition for a binary tree node. * public class TreeNode { *…

问题 给出一棵二叉树,找出它的最小深度. 最小深度是指从根节点沿着最短路径下降到最近的叶子节点所经过的节点数. 初始思路 不难看出又是一个需要层次遍历二叉树的题目,只要在112基础上作出简单修改即可得出答案. class Solution { public: int minDepth(TreeNode *root) { if(!root) { ; } treeLevel_[].clear(); treeLevel_[].clear(); depth_ = ; bool flag = false;…