zoj 1221 Risk

#include <stdio.h>#include <string.h>#include <algorithm>using namespace std;const int inf = 999999999;int map[30][30];void floyd(){    int i,j,k;    for(k = 1; k<=20; k++)        for(i = 1; i<=20; i++) for(j = 1; j<=20; j++) {     if(map[i][j]>map[i][k]+map[k][j])         map[i][j] = map[i][k]+map[k][j]; }}int main(){    int i,j,n,x,y,cas = 1;    while(~scanf("%d",&n))    {        for(i = 0; i<=22; i++)        { for(j = 0; j<=22; j++)     map[i][j] = inf;        }        for(i = 1; i<=n; i++)        { scanf("%d",&x); map[1][x] = map[x][1] = 1;        }        for(i = 2; i<=19; i++)        { scanf("%d",&n); while(n--) {     scanf("%d",&x);     map[i][x] = map[x][i] = 1; }        }        floyd();        printf("Test Set #%dn",cas++);        scanf("%d",&n);        while(n--)        { scanf("%d%d",&x,&y); printf("%d to %d: %dn",x,y,map[x][y]);        }        printf("n");    }    return 0;}