bee2836.cpp

/*
 * Contest : Beecrowd
 * Problem : 2836 - Wifi
 * Link    : https://judge.beecrowd.com/pt/problems/view/2836
 */

#include <bits/stdc++.h>
using namespace std;
using ll = long long;

#define fastio ios::sync_with_stdio(0); cin.tie(0);

typedef struct {
  int x1, x2, y1, y2;
} pontos;

vector<pontos> ret;

bool cmp(pontos a, pontos b) {
  if (a.x1 != b.x1) return a.x1 < b.x1;
  if (a.y1 != b.y1) return a.y1 < b.y1;
  if (a.x2 != b.x2) return a.x2 < b.x2;

  return a.y2 < b.y2;
}

int main() {
  fastio

  int n; cin >> n;
  int x1, x2, y1, y2;
  ret.resize(n);
  for (int i = 0; i < n; ++i) {

    cin >> x1 >> y1;
    cin >> x2 >> y2;

    ret[i].x1 = min(x1, x2);
    ret[i].x2 = max(x1, x2);

    ret[i].y1 = min(y1, y2);
    ret[i].y2 = max(y1, y2);
  }

  sort(ret.begin(), ret.end(), cmp);
  int ans = 0;
  for (int i = 0; i < n; ++i) {
    pontos a, b;
    a = ret[i];

    bool flag = true;
    for (int j = i + 1; j < n; ++j) {
      b = ret[j];

      if (b.x1 > a.x1 && b.x1 < a.x2 && b.y1 > a.y1 && b.y1 < a.y2) {
        fprintf(stderr, "\no retangulo (%i, %i) (%i, %i) ", b.x1, b.y1, b.x2, b.y2);
        fprintf(stderr, "está dentro do retangulo (%i, %i) (%i, %i)\n", a.x1, a.y1, a.x2, a.y2);
        flag = false;
        break;
      }
    }

    ans += flag;
  }

  cout << ans << "\n";

  return 0;
}