dijkstra preiority_queue优化 紫书学习

#include<bits/stdc++.h>
using namespace std;
const int maxn=1000+10;
const int INF=1000000000;
struct Edge{
	int v,d;
	Edge(int v,int d):v(v),d(d){}
	bool operator<(const Edge&a)
	const{return d>a.d;}
};

vector<Edge>Map[maxn];
int vis[maxn],dis[maxn];
void dijkstra(int n){
	priority_queue<Edge>Q;
	for(int i=1;i<=n;i++)dis[i]=INF;

	dis[1]=0;
	Q.push(Edge(1,dis[1]));
	while(!Q.empty()){
		Edge now=Q.top();Q.pop();
		if(vis[now.v])continue;
		vis[now.v]=1;
		printf("edge:%d\n",now.v);
		for(int i=0;i<Map[now.v].size();i++){
			Edge next=Map[now.v][i];
			if(dis[next.v]>dis[now.v]+next.d){
				dis[next.v]=dis[now.v]+next.d;
				Q.push(Edge(next.v,dis[next.v]));
				printf("%d %d\n",next.v,dis[next.v]);
			}
		}
	}
}
int main(){
	int n,m;
	while(scanf("%d%d",&n,&m)==2 &&n){
		for(int i=1;i<=n;i++)Map[i].clear();
		memset(vis,0,sizeof(vis));
		memset(dis,0,sizeof(dis));
		while(m--){
			int a,b,c;
			scanf("%d%d%d",&a,&b,&c);
			Map[a].push_back(Edge(b,c));
			Map[b].push_back(Edge(a,c));
		}
		dijkstra(n);
		for(int i=1;i<=n;i++)printf("%d ",dis[i]);
		printf("\n");
	}
	return 0;
}
/*
5 7
1 2 2
1 3 1
1 4 6
2 4 1
3 4 4
3 5 10
4 5 1
*/

转载于:https://www.cnblogs.com/zhizhaozhuo/p/9594229.html