Codeforces Round #191 (Div. 2) E题

状态压缩DP，算sum，本来是枚举的，结果TLE了。。

#include <iostream>
#include <cstring>
#include <cstdio>
#include <queue>
#include <cstdlib>
using namespace std;
#define MOD 1000000007
int p[10001];
int hash[1<<24];
int sum[1<<24];
int k[3];
int lowbit(int t)
{
    return t&(-t);
}
int main()
{
    int n,m,i,j;
    scanf("%d",&n);
    for(i = 0; i < n; i ++)
    {
        scanf("%d",&p[i]);
    }
    scanf("%d",&m);
    for(i = 1; i <= m; i ++)
    {
        scanf("%d",&k[i]);
    }
    if(m == 1) k[2] = k[1];
    hash[0] = 1;
    for(i = 0;i < n;i ++)
    sum[1<<i] = p[i];
    for(i = 1; i < (1<<n); i ++)
    {
        sum[i] = sum[i-lowbit(i)] + sum[lowbit(i)];
        if(sum[i] == k[1]||sum[i] == k[2])
            continue;
        for(j = i; j > 0; j -= lowbit(j))
        {
            hash[i] += hash[i-lowbit(j)];
            if(hash[i] > MOD)
            hash[i] -= MOD;
        }
    }
    printf("%d
",hash[(1<<n)-1]);
    return 0;
}