July Cook-Off 2017

Chang and Bitwise OR 

分析:因为按位或最后肯定小于等于加，所以把所有数按位或即可

#include "iostream"
#include "cstdio"
#include "cstring"
using namespace std;
const int maxn=1e5+10;
long long a[maxn];
int T,n;
int main()
{
    cin>>T;
    while(T--)
    {
        scanf("%d",&n);
        long long res=0;
        for(int i=1;i<=n;i++){
            cin>>a[i];
            res|=a[i];
        }
        cout<<res<<endl;
    }
    return 0;
}

Chang and the Perfect Function

分析：我们求出每一个sqrt(i*i+y)-i,最后加起来即可

#include "iostream"
#include "cstdio"
#include "cstring"
#include "string"
#include "cmath"
using namespace std;
long long a,b;
int main()
{
    cin>>a>>b;
    long long d=0;
    for(long long i=1;i<=a;i++){
        long long res=i*i+b;
        long long c=sqrt(res);
        d+=c-i;
    }
    cout<<d<<endl;
}