力扣-面试题04.01题 节点间通路（C++）- BFS

题目链接：https://leetcode.cn/problems/route-between-nodes-lcci/
题目如下：

class Solution {
public:
    bool findWhetherExistsPath(int n, vector>& graph, int start, int target) {
        //存储图的各条边
        unordered_map> umap;
        for(auto e:graph){
            umap[e[0]].push_back(e[1]);
        }

        //bfs，将起始节点放入队列，依次，获得所有以此为起点的终节点
        queue que;
        que.push(start);

        while(que.size()){
            auto t=que.front();
            que.pop();

            for(auto e:umap[t]){
                que.push(e);
                if(e==target) return true;
            }
        }

        return false;
    }
};