UVA 567 - Risk

最短路问题：floyd算法：

注意：输出格式

#include<stdio.h>
#define MAXN 200int a, b, n, d[30][30], num;
void init()
{num = 0;while(scanf("%d",&a) == 1){for(int i = 1; i <= 20; i ++)for(int j = 1; j <= 20; j ++)if(i == j) d[i][j] = 0;else d[i][j] = MAXN;if(a != 0)for(int i = 0; i < a; i ++){scanf("%d",&b);d[1][b] = 1;d[b][1] = 1;}for(int i = 2; i < 20; i ++){scanf("%d",&a);if(a != 0)for(int j = 0; j < a; j ++){scanf("%d",&b);d[i][b] = 1;d[b][i] = 1;}}for(int k = 1; k <= 20; k ++)for(int i = 1; i <= 20; i ++){for(int j = 1; j <= 20; j ++)d[i][j] = (d[i][j] < (d[i][k] + d[k][j]) )? d[i][j] : (d[i][k] + d[k][j]);}num ++;printf("Test Set #%d\n",num);scanf("%d",&n);for(int i = 0; i < n; i ++){scanf("%d%d",&a,&b);printf("%2d to %2d: %d\n",a,b,d[a][b]);}puts("");}    
}int main()
{init();return 0;
}