[poj2387] Til the Cows Come Home

题目链接

思路：dijkstra模板

#include <iostream>#include <cstdio>#include <cstring>using namespace std;#define INF 1000000000int m,n,x,y,z;int w[2005][2005];int d[2005],vis[2005];void dijkstra(){    for(int i=1;i<=n;i++) d[i]=INF;    d[1]=0;    for(int i=1;i<=n;i++)    {        int x,m=INF;        for(int j=1;j<=n;j++)        {            if(m>d[j]&&!vis[j]){                m=d[j];                x=j;            }        }        vis[x]=1;        for(int j=1;j<=n;j++)        d[j]=min(d[j],d[x]+w[x][j]);    }}int main(){    scanf("%d%d",&m,&n);    memset(w,63,sizeof(w));    memset(vis,0,sizeof(vis));    for(int i=1;i<=m;i++){        scanf("%d%d%d",&x,&y,&z);        if(z<w[x][y])        w[x][y]=w[y][x]=z;    }    dijkstra();    cout<<d[n]<<endl;    return 0;}