然而改了一点莫名奇妙的又过了
```cpp
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cstring>
#include <string>
#include <cstdlib>
#include <cmath>
#include <stack>
#include <queue>
#include <vector>
#include <map>
#include <set>
#include<bitset>
#include<list>
#include <algorithm>
#define pii pair<int,int>
#define pll pair<LL,LL>
#define pil pair<int,LL>
#define pli pair<LL,int>
#define pdd pair<db,db>
#define se second
#define fi first
#define endl '\n'
#define rep(i,a,b) for (register int i=a;i<b;++i)
#define per(i,a,b) for (register int i=a;i>b;--i)
#define MEM(a,x) memset(a,x,sizeof(a))
#define M(x) ((x)%MOD)
#define all(x) (x).begin(),(x).end()
#define db double
#define eps 1e-9
typedef long long LL;
typedef unsigned long long ULL;
using namespace std;
const int MOD=9901;
const int N=4e5+10;
pii p[N];
LL ans=1e18;
int n;
inline LL dist(int i,int j)
{
return 1ll*(p[i].fi-p[j].fi)*(p[i].fi-p[j].fi)+1ll*(p[i].se-p[j].se)*(p[i].se-p[j].se);
}
inline bool cmp(int a,int b)
{
return p[a].se<p[b].se;
}
inline void cal(int l,int r)
{
if(l>=r) return;
int m=l+r>>1;
cal(l,m),cal(m+1,r);
vector<int>v;
rep(i,l,r+1) if(1ll*(p[m].fi-p[i].fi)*(p[m].fi-p[i].fi)<ans) v.push_back(i);
sort(all(v),cmp);
rep(i,0,v.size()){
rep(j,i+1,v.size()){
if(1ll*(p[v[i]].se-p[v[j]].se)*(p[v[i]].se-p[v[j]].se)>=ans) break;
ans=min(ans,dist(v[i],v[j]));
}
}
}
inline void solve()
{
cin>>n;
rep(i,0,n) cin>>p[i].fi>>p[i].se;
sort(p,p+n);
cal(0,n-1);
cout<<ans;
}
int main()
{
ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
int _=1;
//cin>>_;
while(_--){
solve();
}
return 0;
}
```
by wild_pointer @ 2023-01-16 01:39:12