HDU 4901 The Romantic Hero

 1 #include<algorithm>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<iostream>
 5 using namespace std;
 6 const int q=1000000007;
 7 const int mxn=1200;
 8 int n,k;
 9 int a[mxn];
10 int f[mxn][mxn],t[mxn][mxn];
11 int main(){
12     int T;
13     scanf("%d",&T);
14     while(T--){
15         memset(f,0,sizeof(f));
16         memset(t,0,sizeof(t));
17         scanf("%d",&n);
18         int i,j;
19         for(i=1;i<=n;i++)scanf("%d",&a[i]);
20         //xor
21         f[0][0]=1; //边界
22         for(i=1;i<=n;i++){
23           for(j=0;j<1024;j++){
24               f[i][j]=(f[i-1][j]+f[i-1][j^a[i]])%q;
25           }
26         }
27         //and
28         for(i=1;i<=n;i++)t[i][a[i]]=1;
29         for(i=n;i>=1;i--){
30             for(j=0;j<1024;j++){
31                 t[i][j]=t[i+1][j];//不选
32             }
33             for(j=0;j<1024;j++){//选
34                 t[i][j&a[i]]=(t[i][j&a[i]]+t[i+1][j])%q;
35             }
36             t[i][a[i]]=(t[i][a[i]]+1)%q;
37         }
38         //
39         int ans=0;
40         for(i=1;i<n;i++){
41             for(j=0;j<1024;j++)
42                 ans=(ans+(long long)t[i+1][j]*f[i-1][j^a[i]])%q;//累加结果
43         }
44         printf("%d\n",ans);
45     }
46     return 0;
47 }