Cod sursa(job #2863312)

Utilizator roberttrutaTruta Robert roberttruta Data 6 martie 2022 16:11:32
Problema Cele mai apropiate puncte din plan Scor 75
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.57 kb
#include <fstream>
#include <algorithm>
#include <cmath>
#include <iomanip>

using namespace std;
ifstream f("cmap.in");
ofstream g("cmap.out");

struct point
{
    int x,y;
}v[100005];

bool criteria(point a, point b)
{
    if(a.x == b.x)
        return a.y < b.y;
    return a.x < b.x;
}

double dis(int a, int b)
{
    long long x1 = v[a].x;
    long long x2 = v[b].x;
    long long y1 = v[a].y;
    long long y2 = v[b].y;
    long long x = (x1 - x2)*(x1 - x2);
    long long y = (y1 - y2)*(y1 - y2);
    return sqrt(x + y);
}

double combine(int s, int d, double width)
{
    int mij = (s+d)/2;
    double Min=width;
    for(int i=mij; i>=s; i--)
    {
        if(v[mij].x-v[i].x >= width)
            break;
        for(int j=mij+1; j<=d; j++)
        {
            if(v[j].x-v[mij].x >= width)
                break;
            Min = min(Min, dis(i, j));
        }
    }
    return Min;
}

double divide_et_impera(int s, int d)
{
    double Min;
    if(d-s <= 2)
    {
        Min = dis(s, s+1);
        if(d-s == 2)
        {
            Min = min(Min, dis(s, s+2));
            Min = min(Min, dis(s+1, s+2));
        }
        return Min;
    }
    int mij = (s+d)/2;
    Min = min(divide_et_impera(s, mij), divide_et_impera(mij+1, d));
    Min = min(Min, combine(s, d, Min));
    return Min;
}

int main()
{
    int n,i;
    f>>n;
    for(i=1; i<=n; i++)
    {
        f>>v[i].x;
        f>>v[i].y;
    }
    sort(v+1, v+1+n, criteria);

    g<<setprecision(6)<<fixed<<divide_et_impera(1, n);

    return 0;
}