Codeforces Round #330 (Div. 1) C. Edo and Magnets（暴力+矩形覆盖点）

#include<bits/stdc++.h>
using namespace std;
#define LL long long
#define pb push_back-
#define X first
#define Y second
#define cl(a,b) memset(a,b,sizeof(a))
typedef pair<int,int> P;
const int maxn=300005;
const LL inf=1<<27;
const LL mod=1e9+7;

struct point{
LL x,y;
}p[maxn];
int x1[maxn],x2[maxn],Y1[maxn],y2[maxn];
///排序
bool cmp1(int a,int b){
return p[a].x<p[b].x;
}
bool cmp2(int a,int b){
return p[a].x>p[b].x;
}
bool cmp3(int a,int b){
return p[a].y<p[b].y;
}
bool cmp4(int a,int b){
return p[a].y>p[b].y;
}
int used[maxn];
int main(){
int n,k;
scanf("%d%d",&n,&k);
for(int i=1;i<=n;i++){
LL X1,X2,y1,Y2;
scanf("%lld%lld%lld%lld",&X1,&y1,&X2,&Y2);
p[i].x=X1+X2;//放大2倍
p[i].y=y1+Y2;
x1[i]=x2[i]=Y1[i]=y2[i]=i;
}

sort(x1+1,x1+1+n,cmp1);
sort(x2+1,x2+1+n,cmp2);
sort(Y1+1,Y1+1+n,cmp3);
sort(y2+1,y2+1+n,cmp4);

LL ans=1LL<<62;
int flag=0;
for(int a=0;a<=k;a++){
for(int b=0;b<=k;b++){
for(int c=0;c<=k;c++){
for(int d=0;d<=k;d++){///暴力枚举
flag++;
int cnt=0;
for(int i=1;i<=a;i++)if(used[x1[i]]!=flag){used[x1[i]]=flag;cnt++;}
for(int i=1;i<=b;i++)if(used[x2[i]]!=flag){used[x2[i]]=flag;cnt++;}
for(int i=1;i<=c;i++)if(used[Y1[i]]!=flag){used[Y1[i]]=flag;cnt++;}
for(int i=1;i<=d;i++)if(used[y2[i]]!=flag){used[y2[i]]=flag;cnt++;}
if(cnt!=k)continue;///每次删除k个点
LL maxx=-1LL<<62,minx=1LL<<62,maxy=-1LL<<62,miny=1LL<<62;
for(int i=1;i<=n;i++)if(used[i]!=flag){
maxx=max(p[i].x,maxx);
minx=min(p[i].x,minx);
maxy=max(p[i].y,maxy);
miny=min(p[i].y,miny);
}
LL x=maxx-minx,y=maxy-miny;
if(x%2==1)x++;
if(y%2==1)y++;
x=max(2LL,x);
y=max(2LL,y);
ans=min(ans,x*y);
}
}
}
}
printf("%lld\n",ans/4);
return 0;
}