111. Minimum Depth of Binary Tree（Tree）

https://leetcode.com/problems/minimum-depth-of-binary-tree/description/

题目：求二叉树的最小深度

思路：直接用BFS

class Solution {
public:
    int minDepth(TreeNode* root) {
        int re = 1;
        if(!root) return 0;
        TreeNode *q[10000];
        int l=0,r=1;
        int num = 1,next_num = 0;
        q[l] = root;
        while(l<r){
             TreeNode *temp = q[l];
             num--;
             if(!temp->left&&!temp->right)  return re;
             if(temp->left)  q[r] = temp->left,r++,next_num++;
             if(temp->right) q[r] = temp->right,r++,next_num++;
             if(num==0){
                num = next_num;
                next_num = 0;
                re++;
             }
            l++;
        }
        return re;
    }
};