2157.cpp

杭电 acm部分代码 有兴趣的可以下载 谢谢

#include <iostream>
using namespace std;
int hash[30][30];
int dest[30][30][30];
int main()
{
    long m, n, t;
    long a, b, i, j, k, o;
    while (scanf("%ld %ld", &n, &m) == 2)
    {
        if (m == 0 && n == 0)
        {
            break;
        }
        memset(hash, 0, sizeof(hash));
        memset(dest, 0, sizeof(dest));

        for (i = 0; i < m; i++)
        {
            scanf("%ld %ld", &a, &b);
            hash[a][b] = 1;
        }

		memcpy(dest[0], hash, sizeof(hash));

        for (i = 1; i < 21; i++)
        {
            for (j = 0; j < n; j++)
            {
                for (k = 0; k < n; k++)
                {
                    for (o = 0; o < n; o++)
                    {
                        dest[i][j][k] += (dest[i - 1][j][o] * hash[o][k]) % 1000; 
                    }
                }
            }
        }
        scanf("%ld", &t);
        for (i = 0; i < t; i++)
        {
			scanf("%ld %ld %ld", &a, &b, &o);
			if (a == b && o == 0)
			{
				printf("1\n");
			}
			else
			{
				printf("%ld\n", dest[o - 1][a][b] % 1000);
			}
        }
    }
    return 0;
}