hdu 1385 Floyd 输出路径

Floyd 输出路径

Sample Input
5
0 3 22 -1 4
3 0 5 -1 -1
22 5 0 9 20
-1 -1 9 0 4
4 -1 20 4 0
5 17 8 3 1 //收费
1 3 //起点 终点
3 5
2 4
-1 -1
0

Sample Output
From 1 to 3 :
Path: 1-->5-->4-->3
Total cost : 21

From 3 to 5 :
Path: 3-->4-->5
Total cost : 16

From 2 to 4 :
Path: 2-->1-->5-->4
Total cost : 17

 # include <iostream>
 # include <cstdio>
 # include <cstring>
 # include <string>
 # include <algorithm>
 # include <cmath>
 # include <map>
 # define LL long long
 using namespace std ;

 const int MAXN =  ;
 const int INF = 0x3f3f3f3f;
 int dis[MAXN][MAXN];
 int b[MAXN] ;
 int path[MAXN][MAXN] ;
 int n ;

 void floyed()//节点从1~n编号
 {
     int i,j,k;
     for (i = ; i <= n; i++)
         for (j = ; j <= n; j++)
             path[i][j] = j;  //记录路径数组初始化，表示从i到j经过的第一个站
     for(k=;k<=n;k++)
        for(i=;i<=n;i++)
          for(j=;j<=n;j++)
          {
              int t = dis[i][k]+dis[k][j] + b[k] ;
              if (t < dis[i][j])
              {
                  dis[i][j] = t ;
                  path[i][j] = path[i][k] ;
              }
              else if (t == dis[i][j] && path[i][k] < path[i][j])
                  path[i][j] = path[i][k] ;

          }

 }

 int main()
 {
    // freopen("in.txt","r",stdin) ;
     while (scanf("%d" , &n) , n)
     {
         int i , j ;
         for (i =  ; i <= n ; i++)
             for (j =  ; j <= n ; j++)
         {
             scanf("%d" , &dis[i][j]) ;
             if (dis[i][j] == -)
                 dis[i][j] = INF ;
         }
         for (i =  ; i <= n ; i++)
             scanf("%d" , &b[i]) ;
         floyed() ;
         int u , v ;
         while(scanf("%d %d" , &u , &v) )
         {
             if (u == - && v == -)
                 break ;
             printf ("From %d to %d :\n", u, v);
             printf ("Path: %d", u);
             int t = u;
             while (u != v)
             {
                 printf ("-->%d", path[u][v]);
                 u = path[u][v];
             }
             printf ("\nTotal cost : %d\n\n", dis[t][v]);
         }

     }
     return ;
 }