Cod sursa(job #1216595)

Utilizator mariusn01Marius Nicoli mariusn01 Data 5 august 2014 00:46:20
Problema Oypara Scor 50
Compilator cpp Status done
Runda Arhiva de probleme Marime 2.68 kb
#include <fstream>
#include <vector>
#include <algorithm>
#define DIM 100010
using namespace std;
ifstream fin("oypara.in");
ofstream fout("oypara.out");

vector< pair<int, int> > P, Q;
pair<int, int> S[DIM];
pair<int, int> aux;

int n, x, y, z, i, cp, cq, ok;

long long det(const pair<int, int> &a, const pair<int, int> &b, const pair<int, int> &c) {
    return (1LL*b.first-a.first)*(c.second-a.second) - (1LL*c.first-a.first)*(b.second-a.second);
}

int cmp( const pair<int, int> &a, const pair<int, int> &b  ) {
    return det(aux, a, b) > 0;
}

void infasuratoare(vector< pair<int, int> > &P) {

    int p = 0;
    for (int j=0; j<P.size(); j++)
        if (P[j].first < P[p].first ||
            (P[j].first == P[p].first && P[j].second < P[p].second))
            p = j;

    aux = P[p];
    P[p] = P[0];
    P[0] = aux;

    sort(P.begin()+1, P.end(), cmp);

    S[1] = P[0];
    S[2] = P[1];
    int k = 2;

    for (int j=2;j<P.size();j++) {
        while (k >= 2 && det(S[k-1], S[k], P[j]) <= 0  ) {
            k--;
        }
        S[++k] = P[j];
    }

    P.clear();
    while (k) {
        P.push_back(S[k--]);
    }
}

inline int next(vector< pair<int, int> > &P, int c) {
    return ((c!=P.size()-1) ? c+1 : 0);
}

inline int prev(vector< pair<int, int> > &P, int c) {
    return ((c==0) ? P.size()-1 : c-1);
}

int main() {
    fin>>n;
    for (i=1;i<=n;i++) {
        fin>>x>>y>>z;
        P.push_back(make_pair(x, y));
        Q.push_back(make_pair(x, z));
    }

    infasuratoare(P);
    infasuratoare(Q);

/*
    for (i=0;i<Q.size();i++)
        fout<<Q[i].first<<" "<<Q[i].second<<"\n";
*/

    cp = P.size()-1;

    cq = 0;

    int nxt, prv;


    do {
        if (((det(P[cp], Q[cq], Q[prev(Q, cq)]) >= 0) && (det(P[cp], Q[cq], Q[next(Q, cq)]) >= 0))
        && !(det( Q[cq], P[cp],  P[nxt =next(P, cp)]) <= 0 && det( Q[cq], P[cp], P[prv = prev(P, cp)]) <= 0))
            break;
        else
            cq = prev(Q, cq);
    } while(1);


    do {
        if (det( Q[cq], P[cp],  P[nxt =next(P, cp)]) >= 0 && det( Q[cq], P[cp], P[prv = prev(P, cp)]) >= 0) {
            ok = 1;
            break;
        }
        cp = next(P, cp);

        do {
            x=det(P[cp], Q[cq], Q[prv = prev(Q, cq)]);
            y=det(P[cp], Q[cq], Q[nxt = next(Q, cq)]);
            if ((x >= 0) && (y >= 0))
                break;
            else
                cq = prev(Q, cq);
        } while(1);

        if (cp == P.size()-1) {
            ok = 0;
            break;
        }

    } while (1);

    fout<<P[cp].first<<" "<<P[cp].second<<" "<<Q[cq].first<<" "<<Q[cq].second<<"\n";

    return 0;
}