Cod sursa(job #2286792)

Utilizator HD650Stoicescu Adrian Nicolae HD650 Data 20 noiembrie 2018 19:32:13
Problema Cele mai apropiate puncte din plan Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.65 kb
#include <iostream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
using namespace std;
const int NMAX = 100001;
ifstream f("cmap.in");
ofstream g("cmap.out");
struct punct
{
    int x, y;
};

punct v[NMAX], Tmp[NMAX];
int N;

bool compx(const punct &A, const punct &B)
{
    return A.x < B.x;
}

bool compy(const punct &A, const punct &B)
{
    return A.y < B.y;
}

inline long long patrat(long long x)
{
    return x * x;
}

long long dist2(const punct &A, const punct &B)
{
    return patrat(A.x - B.x) + patrat(A.y - B.y);
}

long long distMin(int p, int u)
{
    long long dmin = 0x7FFFFFFFFFFFFFFFLL;
    for(int i = p; i < u; i++)
        for(int j = i + 1; j <= u; j++)
        {
            long long dij = dist2(v[i], v[j]);
            if(dmin > dij)dmin = dij;
        }
    return dmin;
}

long long calcdist(int p, int u)
{
    if(u - p < 3)
        return distMin(p, u);
    int m = (p + u) / 2;
    long long d1 = calcdist(p, m);
    long long d2 = calcdist(m, u);
    long long dd = min(d1, d2);
    int k = 0;
    for(int i = p; i <= u; i++)
        if(patrat(v[i].x - v[m].x) < dd)
            Tmp[++k] = v[i];
    sort(Tmp + 1, Tmp + k + 1, compy);
    for(int i = 1; i < k; i++)
        for(int j = i + 1; j <= k && patrat(Tmp[j].y - Tmp[i].y) < dd; j++)
        {
            d1 = dist2(Tmp[i], Tmp[j]);
            if(dd > d1)dd = d1;
        }
    return dd;
}

int main()
{
    f >> N;
    for(int i = 1; i <= N; i++)
        f >> v[i].x >> v[i].y;
    sort(v + 1, v + N + 1, compx);
    g << fixed << setprecision(6) << sqrt(calcdist(1, N));
    return 0;
}