Problem p00535 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
using namespace std;
#define int long long
using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;
#define ALL(c) begin(c), end(c)
#define RALL(c) rbegin(c), rend(c)
#define ITR(i, b, e) for (auto i = (b); i != (e); ++i)
#define FORE(x, c) for (auto &x : c)
#define REPF(i, a, n) for (int i = a, i##len = (int)(n); i < i##len; ++i)
#define REP(i, n) REPF(i, 0, n)
#define REPR(i, n) for (int i = (int)(n); i >= 0; --i)
#define SZ(c) ((int)c.size())
#define CONTAIN(c, x) (c.find(x) != end(c))
#define OUTOFRANGE(y, x, h, w) (y < 0 || x < 0 || y >= h || x >= w)
#define dump(...)
const int DX[9] = {0, 1, 0, -1, 1, 1, -1, -1, 0},
          DY[9] = {-1, 0, 1, 0, -1, 1, 1, -1, 0};
#define INF (1001001001)
#define INFLL (1001001001001001001ll)
template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
  ITR(i, begin(v), end(v)) os << *i << (i == end(v) - 1 ? "" : " ");
  return os;
}
template <class T> istream &operator>>(istream &is, vector<T> &v) {
  ITR(i, begin(v), end(v)) is >> *i;
  return is;
}
template <class T> istream &operator>>(istream &is, pair<T, T> &p) {
  is >> p.first >> p.second;
  return is;
}
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> using heap = priority_queue<T, vector<T>, greater<T>>;
//------------------------------------------------------------------------------
struct before_main_function {
  before_main_function() {
#ifdef int
#undef INF
#define INF INFLL
#define stoi stoll
#endif
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << setprecision(15) << fixed;
#define endl "\\n"
  }
} before_main_function;
//------------------8<------------------------------------8<--------------------

signed main() {
  int H, W;
  cin >> H >> W;
  vector<string> s(H);
  cin >> s;

  queue<pii> A, B;
  auto check = [&](int i, int j) {
    if (s[i][j] == '.')
      return false;
    int cnt = 0;
    REP(d, 8) {
      int ii = i + DY[d];
      int jj = j + DX[d];
      if (s[ii][jj] == '.')
        cnt++;
    }
    if (s[i][j] - '0' <= cnt) {
      return true;
    } else {
      return false;
    }
  };
  int ans = 0;
  REP(i, H) {
    REP(j, W) {
      if (check(i, j)) {
        A.push({i, j});
      }
    }
  }
  while (1) {
    if (A.empty())
      break;
    ans++;
    // dump(ans,SZ(A));
    while (!A.empty()) {
      int y = A.front().first;
      int x = A.front().second;
      A.pop();
      s[y][x] = '.';
      B.push({y, x});
    }
    set<pii> next;
    while (!B.empty()) {
      int y = B.front().first;
      int x = B.front().second;
      B.pop();
      REP(d, 8) {
        int yy = y + DY[d];
        int xx = x + DX[d];
        if (check(yy, xx)) {
          next.insert({yy, xx});
        }
      }
    }
    FORE(x, next) A.push(x);
  }
  cout << ans << endl;
  return 0;
}

Error: TLE

Fixed submission:

#include <bits/stdc++.h>
using namespace std;
#define int long long
using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;
#define ALL(c) begin(c), end(c)
#define RALL(c) rbegin(c), rend(c)
#define ITR(i, b, e) for (auto i = (b); i != (e); ++i)
#define FORE(x, c) for (auto &x : c)
#define REPF(i, a, n) for (int i = a, i##len = (int)(n); i < i##len; ++i)
#define REP(i, n) REPF(i, 0, n)
#define REPR(i, n) for (int i = (int)(n); i >= 0; --i)
#define SZ(c) ((int)c.size())
#define CONTAIN(c, x) (c.find(x) != end(c))
#define OUTOFRANGE(y, x, h, w) (y < 0 || x < 0 || y >= h || x >= w)
#define dump(...)
const int DX[9] = {0, 1, 0, -1, 1, 1, -1, -1, 0},
          DY[9] = {-1, 0, 1, 0, -1, 1, 1, -1, 0};
#define INF (1001001001)
#define INFLL (1001001001001001001ll)
template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
  ITR(i, begin(v), end(v)) os << *i << (i == end(v) - 1 ? "" : " ");
  return os;
}
template <class T> istream &operator>>(istream &is, vector<T> &v) {
  ITR(i, begin(v), end(v)) is >> *i;
  return is;
}
template <class T> istream &operator>>(istream &is, pair<T, T> &p) {
  is >> p.first >> p.second;
  return is;
}
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> using heap = priority_queue<T, vector<T>, greater<T>>;
//------------------------------------------------------------------------------
struct before_main_function {
  before_main_function() {
#ifdef int
#undef INF
#define INF INFLL
#define stoi stoll
#endif
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << setprecision(15) << fixed;
#define endl "\\n"
  }
} before_main_function;
//------------------8<------------------------------------8<--------------------

signed main() {
  int H, W;
  cin >> H >> W;
  vector<string> s(H);
  cin >> s;

  queue<pii> A, B;
  auto check = [&](int i, int j) {
    if (s[i][j] == '.')
      return false;
    int cnt = 0;
    REP(d, 8) {
      int ii = i + DY[d];
      int jj = j + DX[d];
      if (s[ii][jj] == '.')
        cnt++;
    }
    if (s[i][j] - '0' <= cnt) {
      return true;
    } else {
      return false;
    }
  };
  int ans = 0;
  REP(i, H) {
    REP(j, W) {
      if (check(i, j)) {
        A.push({i, j});
      }
    }
  }
  while (1) {
    if (A.empty())
      break;
    ans++;
    while (!A.empty()) {
      int y = A.front().first;
      int x = A.front().second;
      A.pop();
      s[y][x] = '.';
      B.push({y, x});
    }
    vector<vector<bool>> checked(H, vector<bool>(W, false));
    while (!B.empty()) {
      int y = B.front().first;
      int x = B.front().second;
      B.pop();
      REP(d, 8) {
        int yy = y + DY[d];
        int xx = x + DX[d];
        if (check(yy, xx) && !checked[yy][xx]) {
          A.push({yy, xx});
          checked[yy][xx] = 1;
        }
      }
    }
  }
  cout << ans << endl;
  return 0;
}