Submission #681553

#	Time	Username	Problem	Language	Result	Execution time	Memory
681553		peijar	Furniture (JOI20_furniture)	C++17	100 / 100	301 ms	27756 KiB

furniture

#include <bits/stdc++.h>
#define int long long
using namespace std;

namespace std {
template <typename T> ostream &operator<<(ostream &out, const vector<T> &vec) {
  out << "[";
  for (int i = 0; i < (int)vec.size(); ++i) {
    out << vec[i];
    if (i + 1 < (int)vec.size())
      out << ", ";
  }
  return out << "]";
}
} // namespace std

void dbg_out() { cout << endl; }
template <typename Head, typename... Tail> void dbg_out(Head H, Tail... T) {
  cout << ' ' << H;
  dbg_out(T...);
}

#ifdef DEBUG
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif

signed main(void) {
  ios_base::sync_with_stdio(false);
  cin.tie(0);

  int nbLig, nbCol;
  cin >> nbLig >> nbCol;

  vector<int> onDiag(nbLig + nbCol - 1);

  vector<vector<bool>> isUseful(nbLig, vector<bool>(nbCol, true));
  vector<vector<int>> cntReach(nbLig, vector<int>(nbCol));
  vector<vector<int>> cntReachRev(nbLig, vector<int>(nbCol));
  for (int lig = 0; lig < nbLig; ++lig)
    for (int col = 0; col < nbCol; ++col) {
      if (lig + 1 < nbLig)
        cntReach[lig + 1][col]++, cntReachRev[lig][col]++;
      if (col + 1 < nbCol)
        cntReach[lig][col + 1]++, cntReachRev[lig][col]++;
      onDiag[lig + col] += 1;
    }

  auto tryDisable = [&](int lig, int col) {
    if (!isUseful[lig][col])
      return true;
    if (onDiag[lig + col] == 1)
      return false;

    queue<pair<int, int>> q;
    q.emplace(lig, col);
    while (!q.empty()) {
      auto [r, c] = q.front();
      q.pop();
      assert(isUseful[r][c]);
      isUseful[r][c] = false;
      onDiag[r + c]--;

      // try right
      if (c + 1 < nbCol) {
        cntReach[r][c + 1]--;
        if (!cntReach[r][c + 1] and isUseful[r][c + 1])
          q.emplace(r, c + 1);
      }
      // try bot
      if (r + 1 < nbLig) {
        cntReach[r + 1][c]--;
        if (!cntReach[r + 1][c] and isUseful[r + 1][c])
          q.emplace(r + 1, c);
      }
      // try left
      if (c > 0) {
        cntReachRev[r][c - 1]--;
        if (!cntReachRev[r][c - 1] and isUseful[r][c - 1])
          q.emplace(r, c - 1);
      }
      // try top
      if (r > 0) {
        cntReachRev[r - 1][c]--;
        if (!cntReachRev[r - 1][c] and isUseful[r - 1][c])
          q.emplace(r - 1, c);
      }
    }
    return true;
  };

  for (int lig = 0; lig < nbLig; ++lig)
    for (int col = 0; col < nbCol; ++col) {
      int x;
      cin >> x;
      if (x)
        assert(tryDisable(lig, col));
    }

  int q;
  cin >> q;
  for (int i = 0; i < q; ++i) {
    for (int lig = 0; lig < nbLig; ++lig)
      dbg(isUseful[lig]);
    dbg(onDiag);
    int lig, col;
    cin >> lig >> col;
    --lig, --col;
    cout << tryDisable(lig, col) << '\n';
  }
}

• Subtask 1: 5 / 5
• Subtask 2: 95 / 95