uva567

题目链接请戳 这里

 

解题思路

用Floyd算法

 

代码

#include<stdio.h>
#include<string.h>
#include<algorithm>
#define N 25
#define INF 1e9;
using namespace std;

int d[N][N];
int n;

void floyd()
{
    
    for(int k = 1; k <= 20; k++)
    for(int i = 1; i <= 20; i++)
        for(int j = 1; j <= 20; j++)
                d[i][j] = min(d[i][j], d[i][k] + d[k][j]);
}

int main()
{
    int x;
    int tests = 0;
    while(scanf("%d", &x) != EOF) {
        for(int i = 1; i <= 20; i++)
            for(int j = 1; j <= 20; j++)
                d[i][j] = INF;
        tests++;
        for(int i = 1; i <= 19; i++) {
            for(int j = 1; j <= x; j++) {
                int u;
                scanf("%d", &u);
                d[i][u] = 1;
                d[u][i] = 1;
            }
            if(i != 19) scanf("%d", &x);
        }
        floyd();
        printf("Test Set #%d\n", tests);
        scanf("%d", &n);
        for(int i = 1; i <= n; i++) {
            int a, b;
            scanf("%d%d", &a, &b);
            printf("%2d to %2d: %d\n", a, b, d[a][b]);
        }
        printf("\n");
    }
    return 0;
}