1129. 热浪最短路

Posted 2021-05-23 幽殇默

https://www.acwing.com/problem/content/description/1131/

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
using namespace std;
const int N=2510;
int g[N][N];
int dist[N];
bool st[N];
int startx,endx;
int n,m;
int Dijkstra()
{
	memset(dist,0x3f,sizeof dist);
	dist[startx]=0;
	
	for(int i=0;i<n;i++)
	{
		int t=-1;
		for(int j=1;j<=n;j++)
		if(!st[j]&&(t==-1||dist[j]<dist[t])) t=j;
		
		for(int j=1;j<=n;j++)
		{
			dist[j]=min(dist[j],dist[t]+g[t][j]);
		}
		
		st[t]=true;
	}
	
	return dist[endx];
}
int main(void)
{
    memset(g,0x3f,sizeof g);
	cin>>n>>m>>startx>>endx;
	while(m--)
	{
		int a,b,c;cin>>a>>b>>c;
		g[a][b]=c,g[b][a]=c;
	} 
	cout<<Dijkstra()<<endl;
	return 0;
}