题目链接：http://poj.org/problem?id=1837
#include <stdio.h>
#include <vector>
using namespace std;
//POJ 1837 Balance
const int MAX = 15001;
int dp[21][MAX]; //dp[i][j]表示放前i个砝码，力矩为j的总方法数
//这里j加了7500
int main() {
dp[0][7500] = 1;
int n, m; //n, m 表示钩子和砝码数
scanf("%d %d", &n, &m);
vector<int> hook(n), weight(m);
for (int i = 0; i < n; ++i)
scanf("%d", &hook[i]);
for (int i = 0; i < m; ++i)
scanf("%d", &weight[i]);
for (int i = 0; i < m; ++i)
for (int j = 0; j < MAX; ++j)
for (int k = 0; k < n; ++k)
dp[i + 1][j] += dp[i][j - weight[i] * hook[k]];
printf("%d", dp[m][7500]);
system("pause");
return 0;
}
