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| #include<bits/stdc++.h>
using namespace std;
const double eps=1e-8,PI=acos(-1.0);
struct point{
double x,y;
point(double u=0.0,double v=0.0):x{u},y{v}{}
point operator+(point r){return point(x+r.x,y+r.y);}
point operator-(point r){return point(x-r.x,y-r.y);}
double operator^(const point &b)const{return x*b.y-y*b.x;}
double operator*(const point &b)const{return x*b.x+y*b.y;}
point operator/(double a){return point(x/a,y/a);}
point &operator=(point r){x=r.x,y=r.y;return *this;}
double norm()const{return x*x+y*y;}
double abs(){return (norm());}
bool operator<(const point &r)const{
return x!=r.x?x<r.x:y<r.y;
}
bool operator==(const point &r)const{
return fabs(x-r.x)<eps&&fabs(y-r.y)<eps;
}
void trans(double b){double tx=x,ty=y;x=tx*cos(b)-ty*sin(b);y=tx*sin(b)+ty*cos(b);}
}a[1000010],b[1000010];
inline bool check(point a,point b,point c){return((c^a)>=0&&(b^c)>=0&&((a-b)^(c-b))>=0);}
inline bool cmp1(const point &a,const point &b){return a.x!=b.x?a.x<b.x:a.y<b.y;}
inline bool cmp2(const point &a,const point &b){return (a^b)==0?(a*a)<(b*b):(a^b)>0;}
int n,m;
void polarsort(){
sort(a+1,a+n+1,cmp1);
for(register int i=2;i<=n;++i)a[i]=a[i]-a[1];
a[1].x=a[1].y=0;sort(a+1,a+n+1,cmp2);
}
void hull(){
polarsort();
b[1]=a[1];b[2]=a[2];b[3]=a[3];m=3;
for(register int i=4;i<=n;++i) {
while(check(a[i],b[m-1],b[m])&&m>2)--m;
b[++m]=a[i];
}
}
double ans=0;
bool cmp(point a,point b){
return a.x*a.x+a.y*a.y<b.x*b.x+b.y*b.y;
}
inline double disx(int x,int y){
return (b[x].x-b[y].x)*(b[x].x-b[y].x);
}
inline double disy(int x,int y){
return (b[x].y-b[y].y)*(b[x].y-b[y].y);
}
inline double dis2x(int x,int y){
return (a[x].x-a[y].x)*(a[x].x-a[y].x);
}
inline double dis2y(int x,int y){
return (a[x].y-a[y].y)*(a[x].y-a[y].y);
}
inline double dis2(int x,int y){
return dis2x(x,y)+dis2y(x,y);
}
inline double dis(int x,int y){
return disx(x,y)+disy(x,y);
}
const long long K1=1e8,K2=1e18;
inline bool dl1(const point &a,const point &b){
return a.x<b.x;
}
inline bool dl2(const point &a,const point &b){
return a.y<b.y;
}
int main(){
scanf("%d",&n);
for(register int i=1;i<=n;++i)scanf("%lf%lf",&a[i].x,&a[i].y);
hull();
sort(b+1,b+m+1,cmp);
int x=1,y=1;
int z[9];
long long sz[9]={0,K1,K1,-K1,-K1,K1,-K1,K2,-K2};
for(register int i=1;i<=m;++i)
if(sz[1]>b[i].x)sz[1]=b[i].x,z[1]=i;
for(register int i=1;i<=m;++i)
if(sz[2]>b[i].y)sz[2]=b[i].y,z[2]=i;
for(register int i=1;i<=m;++i)
if(sz[3]<b[i].x)sz[3]=b[i].x,z[3]=i;
for(register int i=1;i<=m;++i)
if(sz[4]<b[i].y)sz[4]=b[i].y,z[4]=i;
for(register int i=1;i<=m;++i)
if(sz[5]>b[i].x+b[i].y)sz[5]=b[i].x+b[i].y,z[5]=i;
for(register int i=1;i<=m;++i)
if(sz[6]<b[i].x+b[i].y)sz[6]=b[i].x+b[i].y,z[6]=i;
for(register int i=1;i<=m;++i)
if(sz[7]>(long long)1ll*b[i].x*b[i].y)sz[7]=(long long)1ll*b[i].x*b[i].y,z[7]=i;
for(register int i=1;i<=m;++i)
if(sz[8]<(long long)1ll*b[i].x*b[i].y)sz[8]=(long long)1ll*b[i].x*b[i].y,z[8]=i;
for(register int i=1;i<n;++i)
for(register int j=i+1;j<=i+70&&j<=n;++j){
double t=sqrt(dis(i,j));
if(ans<t)x=i,y=j,ans=t;
}
for(register int i=1;i<=n;++i)ans=max(ans,sqrt(dis(i,x)));
for(register int i=1;i<=n;++i)ans=max(ans,sqrt(dis(i,y)));
for(register int i=1;i<n;++i)
for(register int j=n;j>=n-70&&j>=1;--j){
double t=sqrt(dis(i,j));
if(ans<t)x=i,y=j,ans=t;
}
for(register int i=1;i<=n;++i)ans=max(ans,sqrt(dis(i,x)));
for(register int i=1;i<=n;++i)ans=max(ans,sqrt(dis(i,y)));
for(register int i=1;i<n;++i)
for(register int j=1;j<=70&&j<=n;++j){
double t=sqrt(dis(i,j));
if(ans<t)x=i,y=j,ans=t;
}
for(register int i=1;i<=n;++i)ans=max(ans,sqrt(dis(i,x)));
for(register int i=1;i<=n;++i)ans=max(ans,sqrt(dis(i,y)));
for(register int i=1;i<=n;++i)
for(register int j=1;j<=4;++j)ans=max(ans,sqrt(dis(i,z[j])));
for(register int i=1;i<=m;++i)
for(register int j=i+1;j<=i+160&&j<=m;++j){
double t=(dis(i,j));
if(ans<t)x=i,y=j,ans=t;
}
for(register int i=1;i<=m;++i)ans=max(ans,(dis(i,x)));
for(register int i=1;i<=m;++i)ans=max(ans,(dis(i,y)));
for(register int i=1;i<=m;++i)
for(register int j=m;j>=m-160&&j>=1;--j){
double t=(dis(i,j));
if(ans<t)x=i,y=j,ans=t;
}
for(register int i=1;i<=m;++i)ans=max(ans,(dis(i,x)));
for(register int i=1;i<=m;++i)ans=max(ans,(dis(i,y)));
for(register int i=1;i<=m;++i)
for(register int j=1;j<=160&&j<=m;++j){
double t=(dis(i,j));
if(ans<t)x=i,y=j,ans=t;
}
for(register int i=1;i<=m;++i)ans=max(ans,(dis(i,x)));
for(register int i=1;i<=m;++i)ans=max(ans,(dis(i,y)));
for(register int i=1;i<=m;++i)
for(register int j=1;j<=8;++j)ans=max(ans,(dis(i,z[j])));
for(register int times=1;times<=72&&(1.0*clock()/CLOCKS_PER_SEC)<=0.985;++times){
double tmp=0;
for(register int i=1;i<=m&&(1.0*clock()/CLOCKS_PER_SEC)<=0.99;++i){
double t=(dis(i,x));
if(tmp<t)y=i,tmp=t;
}
x=y;ans=max(ans,tmp);
}
printf("%.0lf\n",ans);
return 0;
}
|
