HDOJ-1398 Square Coins

母函数为 g(x) = (1+x+x^2+x^3…) * (1+x^4+x^8….) * (1+x^9+x^18…)…..最后求出x^n的系数即可

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>

using namespace std;
#define maxn 300

int c1[maxn], c2[maxn];
int main()
{
// freopen("in.txt", "r", stdin);
    int n;

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

        for(int i = 2; i * i <= n; i++)
        {
            int s = i * i;
            for(int j = 0; j <= n; j++)
                for(int k = 0; k + j <= n; k += s)
                  c2[k+j] += c1[j];
            for(int j = 0; j <= n; j++)
            {
                c1[j] = c2[j];
                c2[j] = 0;
            }
        }
        cout << c1[n] << endl;
    }
    return 0;
}