Submission #71673503

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Source Code Expand

/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author Anurudh Peduri (codelegend)
 */

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using PII = array<int, 2>;
using VI = vector<int>;

void prec() {}

struct Solver {
  set<PII> pts;

  bool place(int x, int y, bool insert = false) {
    for (int dx : {0, 1}) {
      for (int dy : {0, 1}) {
        const PII p{x + dx, y + dy};
        if (pts.count(p)) return false;
        if (insert) pts.insert(p);
      }
    }
    return true;
  }

  void solve(istream &cin, ostream &cout) {
    int n, m;
    cin >> n >> m;

    int ans = 0;
    while (m--) {
      int x, y;
      cin >> x >> y;
      if (place(x, y)) {
        place(x, y, true);
        ans++;
      }
    }
    cout << ans << '\n';
  }
};

//====== Submission Template; Ignore ========//
struct C2x2Placing {
  int case_num = 0;
  void solve(std::istream &in, std::ostream &out) {
#ifdef PRINT_CASE_NUMBERS
    case_num++;
    out << "Case #" << case_num << ": ";
#endif
    Solver().solve(in, out);
  }
};

int main() {
  ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL);
  prec();
  C2x2Placing solver;
  std::istream &in(std::cin);
  std::ostream &out(std::cout);
  solver.solve(in, out);
  return 0;
}

Submission Info

Judge Result