C :

#include<stdio.h>
int n,x;
long long sum,ans=0,a[20];
int main()
{
	scanf("%d",&n);
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&x);
		for(int j=1;x;x>>=1,j++) if(x&1) a[j]++;
	}
	for(int i=1,j=1;i<=15;i++,j<<=1) ans+=(a[i]*(a[i]-1)+((a[i]*(n-a[i]))<<1))*j; 
	printf("%lld",ans);
}

C++ :

#include<iostream>
#include<cstdio>
using namespace std;
long long shu[20]={0},zui=0,zhi,k,i,l,n,p;//15次方最多 
int main()
{
	scanf("%lld",&n);
	for(i=1;i<=n;i++)
	{
		scanf("%lld",&zhi);
		l=1;
		while(zhi)
		{
			if(zhi&1)shu[l]++;
			zhi>>=1;
			l++;
		}
	}
	l=1;
	for(i=1;i<=15;i++)
	{
		zhi=((shu[i]*(shu[i]-1))>>1);
		zhi*=l;zui+=zhi;
		zhi=((shu[i]*(shu[i]+1))>>1);
		zhi=n*shu[i]-zhi;
		zhi*=l;zui+=zhi;
		zhi=shu[i]*(n-shu[i]);
		zhi*=l;zui+=zhi;
		l<<=1;
	}
	printf("%lld\n",zui);
	return 0;
}