rq462 布布的森林探险

rq462 布布的森林探险

dijkstra

#include < iostream >
using   namespace  std;

int  n,s,t,k,m;
int  cost[ 1024 ][ 1024 ];
int  dis[ 1024 ];
int  vis[ 1024 ];
int  ans;
int  dijkstra( int  u, int  v){
     for ( int  i = 1 ;i <= n; ++ i){
        dis[i] = cost[u][i];
        vis[i] = 1 ;
    }
    dis[u] = 0 ;
    vis[u] = 0 ;
     for ( int  i = 1 ;i < n; ++ i){
         int  min = 0x7FFFFFFF ,minj;
         for ( int  j = 1 ;j <= n; ++ j)
             if (vis[j] && dis[j] < min){
                min = dis[j];
                minj = j;
            }
         if (minj == v)  return  dis[v];
        vis[minj] = 0 ;
         for ( int  j = 1 ;j <= n; ++ j)
             if (vis[j] && dis[j] > dis[minj] + cost[minj][j])
                dis[j] = dis[minj] + cost[minj][j];
    }
}
int  main()
{
     char  ss[ 100 ];
     int  l;
    scanf( " %d%d%d%d%d " , & n, & s, & t, & k, & m);
    gets(ss);
    scanf( " %d " , & l); gets(ss);
    memset(cost, 127 , sizeof (cost));
     int  x,y,c;
     for ( int  i = 1 ;i <= l; ++ i){
        scanf( " %d%d%d " , & x, & y, & c);
        gets(ss);
         if (cost[x][y] > c)
            cost[x][y] = c;
    }
    ans = dijkstra(s,k) + dijkstra(k,t);
     if (ans <= m) printf( " Yes\n " );
     else  printf( " No\n " );
    printf( " %d\n " ,ans);
     return   0 ;
}

spfa

#include < iostream >
using   namespace  std;

int  n,s,t,k,m,ln;
long   long  cost[ 1010 ][ 1010 ];
int  lv[ 1010 ];
int  lw[ 1010 ][ 7010 ];
long   long  ans;
int  que[ 1010 ],head,tail;
long   long  dis[ 1010 ];
int  pre[ 1010 ];
bool  vis[ 1010 ];
long   long  spfa( int  u, int  v){
     for ( int  i = 1 ;i <= n; ++ i){
        dis[i] = 0xFFFFFFF ;
        pre[i] = i;
        vis[i] = 1 ;
    }
    dis[u] = 0 ;
    vis[u] = 0 ;
    que[ 1 ] = u;
    head = tail = 1 ;
     while (head <= tail){
         int  xi = que[(head - 1 ) % n + 1 ],yi;
         for ( int  i = 1 ;i <= lv[xi]; ++ i){
            yi = lw[xi][i];
             if (dis[yi] > dis[xi] + cost[xi][yi]){
                dis[yi] = dis[xi] + cost[xi][yi];
                pre[yi] = xi;
                 if (vis[yi]){
                    tail ++ ;
                    que[(tail - 1 ) % n + 1 ] = yi;
                    vis[yi] = 0 ;
                }
            }
        }
        head ++ ;
        vis[xi] = 1 ;
    }
     return  dis[v];
}
int  main()
{
     char  ss[ 100 ];
    scanf( " %d%d%d%d%d " , & n, & s, & t, & k, & m);
    gets(ss);
    scanf( " %d " , & ln); gets(ss);
    memset(cost, 127 , sizeof (cost));
    memset(lv, 0 , sizeof (lv));
     int  x,y,c;
     for ( int  i = 1 ;i <= ln; ++ i){
        scanf( " %d%d%d " , & x, & y, & c);
        gets(ss);
        lv[x] ++ ;
        lw[x][lv[x]] = y;
         if (cost[x][y] > c)
            cost[x][y] = c;
    }
    ans = spfa(s,k) + spfa(k,t);
     if (ans <= m) printf( " Yes\n " );
     else  printf( " No\n " );
    printf( " %d\n " ,ans);
     return   0 ;
}