Cod sursa(job #2240144)

Utilizator RaduXD1Nicolae Radu RaduXD1 Data 12 septembrie 2018 17:32:43
Problema Cele mai apropiate puncte din plan Scor 25
Compilator cpp Status done
Runda Arhiva educationala Marime 1.44 kb
#include <fstream>
#include <algorithm>
#include <deque>
#include <cmath>
#include <iomanip>
#define x first
#define y second
using namespace std;
ifstream fin ("cmap.in");
ofstream fout("cmap.out");
deque<int> Y;
int n,i;
pair<int,int> v[100001];

int cmp(int a, int b)
{
    if(v[a].y<v[b].y)
        return a<b;
    else
        return b<a;
}

double dist(int i, int j)
{
    return sqrt(1LL*(v[i].x-v[j].x)*(v[i].x-v[j].x)+1LL*(v[i].y-v[j].y)*(v[i].y-v[j].y));
}

double solve(int st, int dr)
{
    int i,j,mid;
    double mini=2000000000,aux;
    if(dr-st+1<=3)
    {
        for(i=st;i<dr;i++)
            for(j=i+1;j<=dr;j++)
            {
                aux=dist(i, j);
                if(mini>aux)
                    mini=aux;
            }
        return mini;

    }
    mid=(st+dr)/2;
    mini=min(solve(st, mid), solve(mid+1, dr));
    for(i=mid;v[mid].x-v[i].x<=mini&&i>=st;i--)
        Y.push_back(i);
    for(i=mid+1;v[i].x-v[mid].x<=mini&&i<=dr;i++)
        Y.push_back(i);
    sort(Y.begin(), Y.end(),cmp);
    while(Y.size())
    {
        for(i=1;i<=7&&i<Y.size();i++)
        {
            aux=dist(Y[0], Y[i]);
            if(mini>aux)
                mini=aux;
        }
        Y.pop_front();
    }
    return mini;
}

int main(){
    fin>>n;
    for(i=1;i<=n;i++)
        fin>>v[i].x>>v[i].y;
    sort(v+1, v+n+1);
    fout<<setprecision(6)<<fixed<<solve(1, n);
    return 0;
}