E. Apollo versus Pan 题解(贡献问题)

题目链接

题目思路

可以转化问题为(largesum_{i=1}^{n} (x_i&x_1+x_i&x_2+...+x_i&x_n)*(x_i|x_1+x_i|x_2+...+x_i|x_n))

然后根据套路二进制求贡献即可

代码

#include<bits/stdc++.h>
#define fi first
#define se second
#define debug cout<<"I AM HERE"<<endl;
using namespace std;
typedef long long ll;
const int maxn=5e5+5,inf=0x3f3f3f3f,mod=1e9+7;
const double eps=1e-6;
int n;
ll a[maxn];
int cnt[100];
signed main(){
    int _;scanf("%d",&_);
    while(_--){
        memset(cnt,0,sizeof(cnt));
        scanf("%d",&n);
        for(int i=1;i<=n;i++){
            scanf("%lld",&a[i]);
            for(int j=0;j<=60;j++){
                if(a[i]&(1ll<<j)){
                    cnt[j]++;
                }
            }
        }
        ll ans=0;
        for(int i=1;i<=n;i++){
            ll temp1=0,temp2=0;
            for(int j=0;j<=60;j++){
                if(a[i]&(1ll<<j)){
                    temp1=(temp1+cnt[j]*((1ll<<j)%mod))%mod;
                    temp2=(temp2+n*((1ll<<j)%mod))%mod;
                }else{
                    temp2=(temp2+cnt[j]*((1ll<<j)%mod))%mod;
                }
            }
            ans=(ans+temp1*temp2)%mod;
        }
        printf("%lld
",ans);
    }
    return 0;
}