打表求组合数
long long int c[600][600];
void init()
{
memset(c, 0, sizeof(c));
for (int i = 0; i <= 505; i++)
{
c[i][1] = i;
c[i][0] = 1;
}
for (int i = 2; i <= 500; i++)
for (int j = 2; j <= i; j++)
{
c[i][j] = (c[i - 1][j] + c[i - 1][j - 1]) % pi;
}
}