2460: [BeiJing2011]元素|线性基|高斯消元|贪心

#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<cstdio>
#include<cstring>
#include<vector>
#include<cmath>
#include<complex>
#include<queue>
#include<map>
#include<set>
#define ll long long
#define N 1005
using namespace std;
ll sc()
{
ll i=0; char c=getchar();
while( c>'9' || c<'0' ) c=getchar();
while( c>='0' && c<='9' )i=i*10+c-'0',c=getchar();
return i;
}
struct W{int x;ll a;}a
;
ll ins[66],ans;
int n;
bool cmp(W a,W b)
{
return a.x>b.x;
}
int main()
{
n=sc();
for(int i=1;i<=n;i++)
a[i].a=sc(),a[i].x=sc();
sort(a+1,a+n+1,cmp);
for(int i=1;i<=n;i++)
{
for(int k=65;k>=0;k--)
{
if((a[i].a>>k)&1)
{
if(!ins[k])
{
ins[k]=a[i].a;
break;
}
a[i].a^=ins[k];
}
}
if(a[i].a)ans+=a[i].x;
}
cout<<ans;
return 0;
}