poj1837 Balance

题意好难懂啊

/**

 * Problem:POJ1837

 * Author:Shun Yao

 * Time:2013.4.29

 * Result:Accepted

 * Memo:DP

 */



#include<iostream>

#include<cstring>

#include<cstdlib>

#include<cassert>

#include<cstdio>

#include<cmath>

#include<ctime>

#include<algorithm>



using namespace std;



long n, g, c[22], w[22], f[22][15005];



int main() {

	static long i, j, k;

	freopen("poj1837.in", "r", stdin);

	freopen("poj1837.out", "w", stdout);

	scanf("%ld%ld", &n, &g);

	for (i = 1; i <= n; ++i)

		scanf("%ld", c + i);

	for (i = 1; i <= g; ++i)

		scanf("%ld", w + i);

	memset(f, 0, sizeof f);

	f[0][7500] = 1;

	for (i = 1; i<= g; ++i)

		for (j = 0; j <= 15000; ++j)

			if (f[i - 1][j])

				for (k = 1; k <= n; ++k)

					f[i][j + c[k] * w[i]] += f[i - 1][j];

	printf("%ld", f[g][7500]);

	fclose(stdin);

	fclose(stdout);

	return 0;

}