【贪心】【线性基】bzoj2460 [BeiJing2011]元素

#include<cstdio>
#include<algorithm>
using namespace std;
typedef long long ll;
ll d[64],p[64];
int cnt;//简化线性基的大小
bool Insert(ll val){//尝试插入线性基，返回是否插入成功
for(int i=62;i>=0;--i){
if(val&(1ll<<i)){
if(!d[i]){
d[i]=val;
break;
}
val^=d[i];
}
}
return val>0;
}
ll QueryMax(){
ll res=0;
for(int i=62;i>=0;--i){
if((res^d[i])>res){
res^=d[i];
}
}
return res;
}
ll QueryMin(){
for(int i=0;i<=62;++i){
if(d[i]){
return d[i];
}
}
return 0;
}
void Rebuild(){//化为简化线性基
for(int i=62;i>=0;--i){
for(int j=i-1;j>=0;--j){
if(d[i]&(1ll<<j)){
d[i]^=d[j];
}
}
}
for(int i=0;i<=60;++i){
if(d[i]){
p[cnt++]=d[i];
}
}
}
ll Kth(ll K){
ll res=0;
if(K>=(1ll<<cnt)){
return -1ll;
}
for(int i=60;i>=0;--i){
if(K&(1ll<<i)){
res^=p[i];
}
}
return res;
}
int n;
struct Point{
ll x,y;
Point(const ll &x,const ll &y){
this->x=x;
this->y=y;
}
Point(){}
};
Point a[1005];
bool cmp(const Point &a,const Point &b){
return a.y>b.y;
}
int main(){
//	freopen("bzoj2460.in","r",stdin);
scanf("%d",&n);
for(int i=1;i<=n;++i){
scanf("%lld%lld",&a[i].x,&a[i].y);
}
sort(a+1,a+n+1,cmp);
ll ans=0;
for(int i=1;i<=n;++i){
if(Insert(a[i].x)){
ans+=a[i].y;
}
}
printf("%lld\n",ans);
return 0;
}