minimum-depth-of-binary-tree——二叉树遍历、链表、广度优先

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.

给定一棵二叉树，找到它的最小深度。最小深度是沿着从根节点到最近叶节点的最短路径的节点数量。

class Solution {
public:
    typedef TreeNode* tree;
    int run(TreeNode *root) {
        if(!root)
            return 0;
        queue<tree> q;
        q.push(root);
        tree cur,last;
        int level=1;
        last=q.back();
        while(q.size()){
            cur=q.front();
            q.pop();
            if(cur->left==NULL&&cur->right==NULL)
                break;
            if(cur->left!=NULL)
                q.push(cur->left);
            if(cur->right!=NULL)
                q.push(cur->right);
            if(last==cur){
                level++;
                last=q.back();
            }
        }
        return level;
        
    }
};