（数学+位运算+推导式子）E : Apollo versus Pan | CF Good Bye 2020

传送门

可以看看这个博客写得还有总结的都很好传送门

ac代码：

#include<iostream>
#include<algorithm>
#include<map>
#include<cstring>
using namespace std;
typedef long long ll;
const int mod=1e9+7;
const int maxn=2e6+10;
ll a[maxn];
ll cnt[119];
int main(){
    int t;
    cin>>t;
    while(t--){
        int n;
        scanf("%d",&n);
        memset(cnt,0,sizeof(cnt));
        for(int i=1;i<=n;i++){
            scanf("%lld",&a[i]);
            for(int j=0;j<=60;j++){
                if((a[i]>>j)&1) cnt[j]++;            
            } 
        }
        ll ans=0;
        for(int i=1;i<=n;i++){
            ll base=1;
            ll t1=0;
            ll t2=0;
            for(int j=0;j<=60;j++){
                if((a[i]>>j)&1){
                    t1=(t1+base*cnt[j]%mod)%mod;
                    t2=(t2+base*n%mod)%mod; 
                } 
                else{
                    t2=(t2+base*cnt[j]%mod)%mod;
                }
                base=(base*2)%mod; 
            }
            ans=(ans+t1*t2%mod)%mod;
        }
        printf("%lld\n",ans);
    }
}

#include<iostream>#include<algorithm>#include<map>#include<cstring>using namespace std;typedef long long ll;const int mod=1e9+7;const int maxn=2e6+10;ll a[maxn];ll cnt[119];int main(){int t;cin>>t;while(t--){int n;scanf("%d",&n);memset(cnt,0,sizeof(cnt));for(int i=1;i<=n;i++){scanf("%lld",&a[i]);for(int j=0;j<=60;j++){if((a[i]>>j)&1) cnt[j]++;} }ll ans=0;for(int i=1;i<=n;i++){ll base=1;ll t1=0;ll t2=0;for(int j=0;j<=60;j++){if((a[i]>>j)&1){t1=(t1+base*cnt[j]%mod)%mod;t2=(t2+base*n%mod)%mod; } else{t2=(t2+base*cnt[j]%mod)%mod;}base=(base*2)%mod; }ans=(ans+t1*t2%mod)%mod;}printf("%lld\n",ans);}}

标签：versus,cnt,Good,int,ll,CF,base,ans,mod
来源： https://www.cnblogs.com/lipu123/p/14619926.html