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[];
 int hash[<<];
 int sum[<<];
 int k[];
 int lowbit(int t)
 {
     return t&(-t);
 }
 int main()
 {
     int n,m,i,j;
     scanf("%d",&n);
     for(i = ; i < n; i ++)
     {
         scanf("%d",&p[i]);
     }
     scanf("%d",&m);
     for(i = ; i <= m; i ++)
     {
         scanf("%d",&k[i]);
     }
     if(m == ) k[] = k[];
     hash[] = ;
     for(i = ;i < n;i ++)
     sum[<<i] = p[i];
     for(i = ; i < (<<n); i ++)
     {
         sum[i] = sum[i-lowbit(i)] + sum[lowbit(i)];
         if(sum[i] == k[]||sum[i] == k[])
             continue;
         for(j = i; j > ; j -= lowbit(j))
         {
             hash[i] += hash[i-lowbit(j)];
             if(hash[i] > MOD)
             hash[i] -= MOD;
         }
     }
     printf("%d\n",hash[(<<n)-]);
     return ;
 }