uva 10105

数学  杨辉三角  多项式系数 

#include <cstdio>

int f[13] = {1};
void init()
{
    for (int  i = 1; i < 13; i++)
        f[i] = f[i - 1] * i;
}
int main ()
{
    init();
    int n,k,a;
    while (scanf ("%d%d", &n, &k) == 2)
    {
        a = f[n];
        for (int i = 0; i < k; i++)
        {
            int m;
            scanf ("%d", &m);
            a /= f[m];
        }
        printf ("%d\n", a);
    }
    return 0;
}