cin的锅
开个sync和tie就过了
```cpp
#include<bits/stdc++.h>
using namespace std;
using i64 = long long;
namespace Basis2D{
constexpr double PI = acosl(-1.);
constexpr double INF = 1e20;
constexpr double EPS = 1e-12;
struct Point{
double x,y;
Point(double _x=0, double _y=0):x(_x),y(_y){}
Point& operator=(const Point&o){
x = o.x; y = o.y;
return *this;
}
friend std::ostream& operator<<(std::ostream&out, const Point&p){
return out<<'('<<p.x<<','<<p.y<<')';
}
bool operator<(const Point&o)const{
return x==o.x?y<o.y:x<o.x;
}
Point operator+(const Point&o)const{
return {x+o.x,y+o.y};
}
Point operator-()const{
return {-x,-y};
}
Point operator-(const Point&o)const{
return (*this) + (-o);
}
double operator*(const Point&o)const{
return dot(o);
}
bool operator==(const Point&o)const{
return between(o,o);
}
double norm()const{
return sqrt((*this) * (*this));
}
double dot(const Point&o)const{
return x*o.x+y*o.y;
}
double cross(const Point&o)const{
return x*o.y-y*o.x;
}
bool between(Point a,Point b)const{
if(abs((a.x-x)*(b.y-y)-(b.x-x)*(a.y-y))>EPS)return false;
if(a.x>b.x)std::swap(a.x,b.x);
if(a.y>b.y)std::swap(a.y,b.y);
return a.x-EPS<=x&&x<=b.x+EPS &&
a.y-EPS<=y&&y<=b.y+EPS;
}
double theta()const{
return x+y?atan2(y,x):-INF;
}
};
using Points = std::vector<Point>;
}
namespace Algorithm2D{
using namespace Basis2D;
std::pair<int,int> closet_pair(const Points&dots){
typedef std::pair<int,int> resultType;
std::vector<int> sorted(dots.size());
std::iota(sorted.begin(),sorted.end(),0);
sort(sorted.begin(),sorted.end(),[&dots](auto a,auto b){
return dots[a] < dots[b];
});
resultType res;
double resv = INF;
function<void(int,int)> rec = [&](int l,int r){
if(r-l<=6){
for(int i=l;i<r;i++){
for(int j=l;j<i;j++){
double tmp = (dots[sorted[i]]-dots[sorted[j]]).norm();
if(tmp<resv)resv=tmp,res={sorted[i],sorted[j]};
}
}
std::sort(sorted.begin()+l,sorted.begin()+r,[&dots](auto a,auto b){
return dots[a].y < dots[b].y;
});
}else{
int mid = (l+r) / 2;
auto· = dots[sorted[mid]];
rec(l, mid); rec(mid, r);
std::inplace_merge(sorted.begin()+l,sorted.begin()+mid,sorted.begin()+r,[&dots](auto a,auto b){
return dots[a].y < dots[b].y;
});
std::array<std::vector<int>, 2> st;
for(int i=l;i<r;i++){
auto&dot = dots[sorted[i]];
if(abs(dot.x-middot.x)>resv)continue;
bool lr = dot < middot;
for(auto it=st[lr].rbegin();it!=st[lr].rend()&&dots[*it].y+resv>=dot.y;it++){
double tmp = (dot-dots[*it]).norm();
if(tmp<resv)resv=tmp,res={sorted[i],*it};
}
st[!lr].push_back(sorted[i]);
}
}
};
rec(0, dots.size());
return res;
}
}
signed main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n;cin>>n;
using namespace Basis2D;
Points dots(n);
for(auto&[x,y]:dots)cin>>x>>y;
auto p = Algorithm2D::closet_pair(dots);
double ansx = (dots[p.first]-dots[p.second]).x;
double ansy = (dots[p.first]-dots[p.second]).y;
cout<<setprecision(0)<<fixed<<(ansx*ansx+ansy*ansy)<<endl;
return 0;
}
```
by _Regenbogen_ @ 2023-09-21 07:03:48
@[cTen_lambda](/user/68189)
by _Regenbogen_ @ 2023-09-21 07:11:27
刚翻了翻记录，你过了
~~我在干什么~~
by _Regenbogen_ @ 2023-09-21 07:12:50
@[_Regenbogen_](/user/791638) 没事谢谢谢谢了♥
by lamkappa @ 2023-09-21 10:36:33