Dijkstra+堆优化 模板

#include<iostream>
#include<cstdio>
#include<queue>
#include<vector>
#include<cstring>
#include<algorithm>
using namespace std;
const int maxn=30000+5; 
struct Edge{
	int from,to,weight;
	Edge(int from,int to,int weight):from(from),to(to),weight(weight){}
};
struct HeapNode{  //prority_queue 中的优先级 
	int u,dist;   //dist: u点到起点的最短路 ,u: 有向边的终点 
	HeapNode(int u,int d):u(u),dist(d){}
	bool operator < (const HeapNode& h) const {
		return dist>h.dist;
	}
};
struct Dijkstra{ //打包在Dijkstra中 
	int n,m;
	vector<Edge> edges;
	vector<int> G[maxn];
	bool done[maxn];
	int dist[maxn];
	int p[maxn];
	Dijkstra(int n):n(n){
		for(int i=0;i<n;i++) G[i].clear();
		edges.clear();
	}
	void AddEdge(int from,int to,int weight){
		edges.push_back(Edge(from,to,weight));
		m=edges.size();
		G[from].push_back(m-1);  //保存from出发的边 
	}
	void dijkstra(int s)
	{
		priority_queue<HeapNode> Q;
		memset(dist,0x7f,sizeof(dis