最短路 HDU - 2544

//1到N的距离

原题连接：http://acm.hdu.edu.cn/showproblem.php?pid=2544

#include<cstdio>
#include<cstring>
const int N=105, INF=9999999;
int d[N], w[N][N],vis[N],n,m;

void Dijkstra(int s){
    memset(d,INF,sizeof(d));
    d[s] = 0;
    memset(vis, 0, sizeof(vis));
    for(int i=1; i<=n; ++i)
    {
        int u=-1;
        int min=INF;
        for(int j=1;j<=n;j++)
        {
            if(vis[j]==0&&d[j]<min)
            {
                u=j;
                min=d[u];
            }
        }
        vis[u] = 1;
        for(int v=1;v<=n;v++)
        {
            if(vis[v]==0&&d[u]+w[u][v]<d[v])
            {
                d[v]=d[u]+w[u][v];
            }
        }
    }
}
int main()
{
    int a,b,c;
    while(~scanf("%d%d",&n,&m)){
        if(n==0&&m==0)
            break;
        for(int i=1; i<=n; ++i)
        {
            w[i][i] = INF;
            for(int j=i+1; j<=n; ++j)
                w[i][j] = w[j][i] = INF;
        }
        for(int i=0; i<m; ++i){
            scanf("%d%d%d",&a,&b,&c);
            w[a][b] = w[b][a] = c;
        }
        Dijkstra(1);
        printf("%d\n", d[n]);
    }
    return 0;
}