LeetCode-111-Minimum Depth of Binary Tree(二叉树的最短路径)

Q:

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.

Analysis:

此题要求返回二叉树根结点到叶子结点最短的距离。

可以采用递归的方法：

Code:

/** * Definition for a binary tree node. * public class TreeNode { *     int val; *     TreeNode left; *     TreeNode right; *     TreeNode(int x) { val = x; } * } */public class Solution {    public int minDepth(TreeNode root) {        if(root==null){            return 0;        }        if (root.left == null && root.right == null) {            return 1;        }        if (root.left == null) {            return minDepth(root.right) + 1;        }        if (root.right == null) {            return minDepth(root.left) + 1;        }        return Math.min(minDepth(root.left), minDepth(root.right)) + 1;    }}