colibri

#include <fstream>
#include <algorithm>
#include <vector>
using namespace std;
ifstream fin ("colibri.in");
ofstream fout ("colibri.out");
const int nMAX = 50e3;
vector<pair<int, double>> poz;
vector<pair<int, double>> neg;
int nul = 0; /// pozitia unui element nul
bool sol[nMAX + 1];
int a[nMAX + 1], b[nMAX + 1], c[nMAX + 1];

bool cmpless(const pair<int, double> &a, const pair<int, double> &b)
{ return (a.second < b.second); }

bool cmpgreater(const pair<int, double> &a, const pair<int, double> &b)
{ return (a.second > b.second); }


int main()
{
   int n, i;
   fin >> n;
   for (i = 1; i <= n; ++i)
   {
      fin >> a[i] >> b[i] >> c[i];
      if (b[i] == 0)
         nul = i;
      else if (a[i] % 2 == 0)
         poz.emplace_back(i, 1.*b[i]/c[i]);
      else if (a[i] % 2 == 1)
         neg.emplace_back(i, -1.*b[i]/c[i]);
   }
   sort(poz.begin(), poz.end(), cmpgreater); // 9, 4.2, 0.6
   sort(neg.begin(), neg.end(), cmpless); // -6.9, -4, -2
   bool solu = 0;
   /// punem toate numerele pozitive mai mari sau egale cu 1.
   for (i = 0; i < poz.size() && poz[i].second >= 1; ++i)
      sol[poz[i].first] = 1,
      solu = 1;
   /// punem perechi de cate 2 numere negative pana cand ..
   for (i = 1; i < neg.size() && neg[i-1].second*neg[i].second >= 1; i += 2)
      sol[neg[i-1].first] = sol[neg[i].first] = 1,
      solu = 1;
   /// problema este ca cele doua for-uri de mai sus s-ar putea sa nu gaseasca nicio solutie.
   if (solu == 0)
   {
      if (poz.size() >= 1 && neg.size() >= 2)
         if (poz[0].second > neg[0].second * neg[1].second)
            sol[poz[0].first] = 1;
         else
            sol[neg[0].first] = sol[neg[1].first] = 1;
      if (poz.size() >= 1 && neg.size() <= 1)
         sol[poz[0].first] = 1;
      if (poz.size() == 0 && neg.size() >= 2)
         sol[neg[0].first] = sol[neg[1].first] = 1;
      if (poz.size() == 0 && neg.size() <= 1)
         if (nul != 0)
            sol[nul] = 1;
         else
            sol[neg[0].first] = 1;
   }
   for (i = 1; i <= n; ++i)
      fout << sol[i];
    return 0;
}