母函数

ACM模版

母函数

/* * 母函数 * c1是保存各项质量砝码可以组合的数目 * c2是中间量，保存每一次的情况 */
const int MAXN = 1e4 + 10;

int n;
int c1[MAXN];
int c2[MAXN];

int main()
{
    while (cin >> n)
    {
        for (int i = 0; i <= n; ++i)
        {
            c1[i] = 1;
            c2[i] = 0;
        }
        for (int i = 2; i <= n; ++i)
        {
            for (int j = 0; j <= n; ++j)
            {
                for (int k = 0; k + j <= n; k += i)
                {
                    c2[j + k] += c1[j];
                }
            }
            for (int j = 0; j <= n; ++j)
            {
                c1[j] = c2[j];
                c2[j] = 0;
            }
        }

        cout << c1[n] << endl;
    }

    return 0;
}