Cod sursa(job #2766777)

Utilizator stefanvoicaVoica Stefan stefanvoica Data 3 august 2021 12:07:51
Problema Cele mai apropiate puncte din plan Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.37 kb
#include<bits/stdc++.h>
#define dim 100002
#define int long long
using namespace std;
ifstream fin ("cmap.in");
ofstream fout("cmap.out");

struct el
{
    int x,y;
}v[dim],w[dim];

inline bool cmp (const el &a1,const el &a2)
{
    if (a1.x==a2.x)
        return a1.y<a2.y;
    return a1.x<a2.x;
}

inline bool cmp2 (const el &a1,const el &a2)
{
    if (a1.y==a2.y)
        return a1.x<a2.x;
    return a1.y<a2.y;
}


long long dist (int i,int j)
{
    long long sol=(v[i].x-v[j].x)*(v[i].x-v[j].x)+(v[i].y-v[j].y)*(v[i].y-v[j].y);
    return sol;
}

long long dist2 (int i,int j)
{
    long long sol=(w[i].x-w[j].x)*(w[i].x-w[j].x)+(w[i].y-w[j].y)*(w[i].y-w[j].y);
    return sol;
}


long long rez (int st,int dr)
{
    if (st==dr)
        return 1e17;
    int nr=0,i,j,mij=(st+dr)/2;
    long long s1=rez(st,mij),s2=rez(mij+1,dr);
    long long s=min(s1,s2);
    for (i=st;i<=dr;i++)
        if ((v[i].x-v[mij].x)*(v[i].x-v[mij].x)<=s)
        w[++nr]=v[i];
    sort(w+1,w+nr+1,cmp2);
    for (i=1;i<=nr;i++)
        for (j=i-1;j>=i-8&&j>=1;--j)
        if (dist2(i,j)<s)
        s=dist2(i,j);
    return s;
}

int32_t main ()
{
    int n,i;
    fin>>n;
    for (i=1;i<=n;i++)
        fin>>v[i].x>>v[i].y;
    sort (v+1,v+n+1,cmp);
    long long sol=rez(1,n);
    long double Q=sqrtl(sol);
    fout<<fixed<<setprecision(6)<<Q;
}