[BeiJing2011][bzoj2460] 元素

无需多言。

直接贪心，从大到小放到线性基里即可。

#include<bits/stdc++.h>
using namespace std;
const int MAXN=100005;
typedef long long ll;
ll ans=0;
struct node{ll x,y; }a[MAXN]; 
int compare(node x,node y) { return x.y>y.y?1:0; }
ll read()
{ll f=1,x=0; char c=getchar();while (c<'0'||c>'9') { if (c=='-') f=-1; c=getchar(); }while (c>='0'&&c<='9') { x=(x<<3)+(x<<1)+c-'0'; c=getchar(); }return x*f;
}
struct Xor_Basis
{int maxsz;ll basis[65];void init(){ memset(basis,0,sizeof basis); maxsz=63; }bool insert(ll x){for (int i=maxsz;i>=0;i--) if ((x>>i)&1)if (basis[i]) x^=basis[i];else { basis[i]=x; break; }return x; }
} QAQ;
int main()
{QAQ.init();int n=read();for (int i=1;i<=n;i++) a[i].x=read(),a[i].y=read();sort(a+1,a+n+1,compare);for (int i=1;i<=n;i++)if (QAQ.insert(a[i].x)) ans+=a[i].y;printf("%lld\n",ans);return 0;
}