BZOJ 3105 [CQOI2013]新Nim游戏 ——线性基

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
 
#include <set>
#include <map>
#include <string>
#include <algorithm>
#include <vector>
#include <iostream>
#include <queue>
using namespace std;
 
#define maxn 100005
#define ll long long
 
int read()
{
    int x=0,f=1; char ch=getchar();
    while (ch<‘0‘||ch>‘9‘) {if (ch==‘-‘) f=-1; ch=getchar();}
    while (ch>=‘0‘&&ch<=‘9‘) {x=x*10+ch-‘0‘; ch=getchar();}
    return x*f;
}
 
int n,a[maxn],b[maxn];
int lb[32];
ll ans;
 
int main()
{
    n=read(); for (int i=1;i<=n;++i) scanf("%d",&a[i]);
    sort(a+1,a+n+1);
    for (int i=1;i<=n;++i) b[i]=a[i],ans+=b[i];
    for (int i=n;i;--i)
    {
        for (int j=31;j>=0;j--)
        {
            if ((a[i]>>j)&1)
            {
                if (!lb[j]) {lb[j]=a[i];break;}
                else a[i]^=lb[j];
            }
        }
        if (a[i]) ans-=b[i];
    }
    cout<<ans<<endl;
}