[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…
[LeetCode]Minimum Depth of Binary Tree 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. 递归和非递归,此提比较简单.广度优先遍历即可.关键之处就在于如何保持访问深度. 下面是4种代码: im…
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…
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. 方法一: 层次遍历.主体的思想不变,程序的主体结构也不变,具体遍历过程参照二叉树的层次遍历.关键在于终止条件,在某一层中,节点遍历的顺序是从左往右的,若是最短路径出现在该层中,则其…
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. 二叉树的经典问题之最小深度问题就是就最短路径的节点个数,还是用深度优先搜索DFS来完成,万能的递归啊...请看代码: /** * Definition for binary tre…
要求:此题正好和Maximum Depth of Binary Tree一题是相反的,即寻找二叉树的最小的深度值:从根节点到最近的叶子节点的距离. 结题思路:和找最大距离不同之处在于:找最小距离要注意(l<r)? l+1:r+1的区别应用,因为可能存在左右子树为空的情况,此时值就为0,但显然值是不为0的(只有当二叉树为空才为0),所以,在这里注意一下即可! 代码如下: struct TreeNode { int val; TreeNode *left; TreeNode *right; Tree…
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节点的最短路径的节点数量.详见:https://leetcode.com/problems/minimum-depth-of-binary-tree/description/ Java实现: 递归实现: /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * Tree…
    题目URL:https://leetcode.com/problems/minimum-depth-of-binary-tree/ 111. Minimum Depth of Binary Tree My Submissions Question Total Accepted: 94580 Total Submissions: 312802 Difficulty: Easy Given a binary tree, find its minimum depth. The minimum…
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…
http://oj.leetcode.com/problems/minimum-depth-of-binary-tree/ 贡献了一次runtime error,因为如果输入为{}即空的时候,出现了crash.其实这种情况也处理了,但是顺序不对,如下: if(root->left == NULL && root->right == NULL) return 1; if(root==NULL ) return 0;如果输入是空的话,会对空->left访问left,但这是错误…