求N维前缀和

 1  #include <iostream>  
 2 #include <cstring>  
 3 #include <cstdlib>  
 4 #include <string>  
 5 #include <cstdio>  
 6 #include <algorithm>  
 7 #include <cmath>  
 8 #include <ctime>  
 9 using namespace std;  
10 int n,A[2000010];  
11 int main() {  
12     scanf("%d",&n);  
13     for(int i = 0;i <= n;i ++) scanf("%d",&A[i]);  
14     for(int i = 0;i <= 19;i ++) {  
15         for(int j = 0;j <= n - 1;j ++) {  
16             if((j >> i) % 2 == 1) {  
17                 A[j] += A[j ^ (1 << i)];  
18             }  
19         }  
20     }  
21     for(int i = 0;i <= n - 1;i ++) printf("%d\n",A[i]);  
22     return 0;  
23 }