Cod sursa(job #1161710)

Utilizator supermitelArdelean Razvan Mitel supermitel Data 31 martie 2014 13:32:56
Problema Cele mai apropiate puncte din plan Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.55 kb
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <cmath>
#define LINF ~(1LL<<63)

using namespace std;

pair<int, int> X[100010], Y[100010], aux[100010];
vector<pair<int, int> > pct;
int n;

inline long long dist(pair<int, int> a, pair<int, int> b)
{
    return 1LL*(a.first - b.first)*(a.first - b.first) + 1LL*(a.second - b.second)*(a.second - b.second);
}

void citire()
{
    scanf("%d", &n);
    for(int i = 0; i < n; i++)
        scanf("%d%d", &X[i].first, &X[i].second);
    sort(X, X+n);
    for(int i = 0; i < n; i++)
    {
        Y[i].first = X[i].second;
        Y[i].second = X[i].first;
    }
}

long long cmap(int st, int dr)
{
    if(dr-st <= 1)
        return LINF;
    if(dr - st == 2)
    {
        if(Y[st] > Y[st+1])
            swap(Y[st], Y[st+1]);
        return dist(Y[st], Y[st+1]);
    }
    int mid = (st+dr)/2;
    long long minim = min(cmap(st, mid), cmap(mid, dr));

    merge(Y+st, Y+mid, Y+mid, Y+dr, aux);
    copy(aux, aux+dr-st, Y+st);

    pct.clear();
    for(int i = st; i < dr; i++)
        if(abs(X[mid].first - Y[i].second) <= minim)
            pct.push_back(Y[i]);

    for(int i = 0; i < pct.size(); i++)
        for(int j = i+1; j < pct.size()  && j-i <= 8; j++)
            minim = min(minim, dist(pct[i], pct[j]));

    return minim;
}

int main()
{
    freopen("cmap.in", "r", stdin);
    freopen("cmap.out", "w", stdout);
    citire();
    long long d = cmap(0, n);
    double rez = sqrt(d);
    printf("%lf\n", rez);
    return 0;
}