这一题重点是建图,,越来越发现建图是解决问题的核心啊,,,,,,
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <string.h>
#include <math.h>
int main()
{
int n,m,x,y,i,j,k;
char name[32][100],temp1[100],temp2[100];
double map[32][32];
int count = 0;
while( ~scanf("%d",&n)!=EOF && n )
{
for(i=1; i<=n; i++)
scanf("%s",name[i]);
scanf("%d",&m);
for(i=1; i<=n; i++)
{
for(j=1;j<=n; j++)
map[i][j] = 0.0;
map[i][i] = 1.0;
}
while(m--)
{ double price;
int x=0,y=0;
scanf("%s%lf%s",temp1,&price,temp2);
for(i=1;i<=n; i++)
{ if(x&&y) break;
if( strcmp(temp1,name[i]) == 0 ) x = i;
if( strcmp(temp2,name[i]) == 0 ) y = i;
}
map[x][y] = price;
}
for(k=1; k<=n; k++)
for(i=1; i<=n; i++)
for(j=1; j<=n; j++)
if( map[i][j] < map[i][k] * map[k][j] )
map[i][j] = map[i][k] * map[k][j];
int success = 0;
for(k=1; k<=n; k++)
if( map[k][k] > 1 )
{success = 1;break; }
if( success == 0 )
printf("Case %d: No\n",++count);
else
printf("Case %d: Yes\n",++count);
}
return 0;
}