2017 ACM-ICPC 亚洲区（西安赛区）网络赛 E. Maximum Flow

小数据打表之后找规律，，
发现了规律是
https://www.jisuanke.com/contest/876/44180
Ｆ题
也可以参考http://blog.youkuaiyun.com/tzc_anruoxin/article/details/78005515

#include<iostream>
#include<cstdio>
#include<cstring>
#include<vector>
#include<string>
#include<algorithm>
#include<set>

using namespace std;

const int maxn = 100;
typedef long long ll;
typedef vector<ll> vec;
typedef vector<vec> mat;
const ll mod= 1e9+7;

ll a[maxn];
ll Pow[maxn];

void init(){
    a[0]=1;
    Pow[0]=1;
    for(ll i=1;i<=62;i++){
        a[i]=a[i-1]*2;
        Pow[i]=(a[i]%mod)*(a[i]%mod)%mod;
    //  cout<<i<<' '<<a[i]<<' '<<Pow[i]<<endl;
    }
}

ll ans(ll x){
    ll sum=0;
    ll n=x;
    for(ll j=0;(1LL<<j)<=x;j++){
        ll temp=(x>>(j+1));
        if(x&(1LL<<j)) temp++;
    //  cout<<temp<<' '<<Pow[j]+1<<endl;
        temp=(temp%mod)*(Pow[j]+1)%mod;
        sum=(sum+temp)%mod;
    }
    ll sub=0;
    for(int i=0;i<=62;i++){
        if(x>=a[i]) {
            ll c1=(a[i]%mod);
            ll c2=(a[i]/2)%mod;
            sub=((sub+(c1*c1-c2*c2))%mod+mod)%mod;
    //      cout<<"-------"<<(a[i]*a[i]-a[i]*a[i]/4)<<endl;
        }
        else break; 
    }
    sum=(sum+mod-sub)%mod;
    return sum;
}

int main(){
    init();
    ll n;
    while(cin>>n){
        cout<<ans(n-1)<<endl;
    }   
    return 0;
}