Dijkstra

d[i]——从源点到 i点的最短距离
f[i]——i的父节点
p[i]——标记i的最短路是否确定：0 不确定；1 确定
d[]置无穷大

d[s]=0;
for (k=1;k<=n;k++){
    min=∞;
    for (j=1;j<=n;j++)
        if (p[j]==0 && d[j]<min){
            min=d[j]; i=j;
        }
    if (min=∞) break;
   
    p=1;
    for (j=1;j<=n;j++)
        if (p[j]==0 && g[i][j]>0 && d[i]+s[i][j]<d[j]){
            d[j]=d[i]+g[i][j];
            f[j]=i;
        }
}

 

08.8.17(在学校学dijkstra)

#include<stdio.h>
    long i,j,k,m,n;
    long dist[101],vis[101];
    long w[101][101];
    long s,t;
void init(){
    long x,y,z;
    scanf("%ld%ld",&n,&m);
    for (i=1;i<=n;i++)
        for(j=1;j<=n;j++)
            w[i][j]=100000000;
     for(i=1;i<=n;i++){
        dist[i]=100000000;    
        vis[i]=1;
     }
     for(i=1;i<=m;i++){
         scanf("%ld%ld%ld",&x,&y,&z);                 
         w[x][y]=z;w[y][x]=z;
     }
     scanf("%ld%ld",&s,&t);         
}
void work(){
    long min;
    dist[s]=0;
    do{
        min=100000000;
        k=0;
        for(i=1;i<=n;i++)
          if(vis[i]==1 && dist[i]<min){
              min=dist[i];
              k=i;            
        }
        if(k==0)break;
        vis[k]=0;
       
        for(i=1;i<=n;i++)
            if(dist[i]>(min+w[k][i]))
                dist[i]=min+w[k][i];
    }while(true);   
}
void out(){
    printf("%ld",dist[t]);
}
main(){
    freopen("dijkstra.in","r",stdin);
    freopen("dijkstra.out","w",stdout);
        init();
        work();
        out();                            
    return 0;
}