Cod sursa(job #2066310)

Utilizator eu3neuomManghiuc Teodor-Florin eu3neuom Data 14 noiembrie 2017 21:15:02
Problema Adapost 2 Scor 85
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.65 kb
#include <bits/stdc++.h>

using namespace std;

ifstream fin("adapost2.in");
ofstream fout("adapost2.out");

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};

const int NMax = 5e4 + 50;
const double eps = 1e-12;

int n;
pair < double, double > points[NMax];

double pointsDistance(const pair < double, double > &a, const pair < double, double > &b) {
    return sqrt((a.first - b.first) * (a.first - b.first) + (a.second - b.second) * (a.second - b.second));
}
double allDistance(const pair < double, double > &x) {
    double ret = (double)0.0;
    for(int i = 1; i <= n; ++i) {
        ret += pointsDistance(points[i], x);
    }

    return ret;
}

int main() {
    fin >> n;

    for(int i = 1; i <= n; ++i) fin >> points[i].first >> points[i].second;
    
    pair < double, double > ans;
    for(int i = 1; i <= n; ++i) {
        ans.first += points[i].first;
        ans.second += points[i].second;
    }
    ans.first /= (double)n;
    ans.second /= (double)n;

    pair < double, double >  auxPair;
    double auxDist;
    double dist = allDistance(ans);

    double hi = 1000.0;
    while(hi >= 0.000001) {
        for(int d = 0; d < 4; ++d) {
            auxPair = {ans.first + dx[d] * hi, ans.second + dy[d] * hi};
            auxDist = 0.0;
            for(int i = 1; i <= n; ++i) {
                auxDist += pointsDistance(points[i], auxPair);
            }

            if(abs(dist - auxDist) < eps) continue;
            if(dist > auxDist) {
                dist = auxDist;
                ans = auxPair;
                d = 0;
            }
        }

        hi /= 2.0;
    }

    fout << fixed << setprecision(4) << ans.first << " " << ans.second;
	return 0;
}