Problem p02680 (C++) — buggy submission, verdict: Runtime Error

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

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<double, double> pdd;
typedef vector<ll> vl;
typedef vector<vector<ll>> vvl;
// typedef vector<vector<ll>> Graph;

const ll mod = 1e9 + 7;
// const ll mod = 998244353;

#define REP(i, n) for (ll i = 0; i < (ll)n; i++)
#define dump(x) cerr << #x << " = " << (x) << endl;
#define spa << " " <<
#define fi first
#define se second

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 (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

template <class S, class T>
ostream &operator<<(ostream &os, const pair<S, T> v) {
  os << "(" << v.first << ", " << v.second << ")";
  return os;
}
template <class T> ostream &operator<<(ostream &os, const vector<T> v) {
  for (int i = 0; i < (int)v.size(); i++) {
    if (i > 0) {
      os << " ";
    }
    os << v[i];
  }
  return os;
}
template <class T> ostream &operator<<(ostream &os, const vector<vector<T>> v) {
  for (int i = 0; i < (int)v.size(); i++) {
    if (i > 0) {
      os << endl;
    }
    os << v[i];
  }
  return os;
}

template <typename T> void debug(vector<vector<T>> &v, ll h, ll w) {
  for (ll i = 0; i < h; i++) {
    cerr << v[i][0];
    for (ll j = 1; j < w; j++)
      cerr spa v[i][j];
    cerr << endl;
  }
};
template <typename T> void debug(vector<T> &v, ll n) {
  if (n != 0)
    cerr << v[0];
  for (ll i = 1; i < n; i++)
    cerr spa v[i];
  cerr << endl;
};

vector<vector<int>> grid_bfs(const vector<string> &S, const char start,
                             const char wall) {
  // start 文字が入っているところから始まる多始点BFS
  // wall があるセルには入れない．この辺は適当に変更

  const int num_dir = 4;
  const int dx[] = {0, -1, 0, 1};
  const int dy[] = {1, 0, -1, 0};

  const int H = S.size();
  const int W = S[0].size();
  vector<vector<int>> dist(H, vector<int>(W, -1));
  queue<pair<int, int>> qu;

  // initialization
  for (int i = 0; i < H; i++) {
    for (int j = 0; j < W; j++) {
      if (S[i][j] == start) {
        qu.emplace(i, j);
        dist[i][j] = 0;
      }
    }
  }

  // BFS
  while (!qu.empty()) {
    auto p = qu.front();
    qu.pop();
    for (int idx = 0; idx < num_dir; idx++) {
      int ni = p.first + dx[idx];
      int nj = p.second + dy[idx];

      if (ni < 0 or nj < 0 or ni > H - 1 or nj > W - 1)
        continue;
      if (dist[ni][nj] != -1)
        continue;
      if (S[ni][nj] == wall)
        continue;

      dist[ni][nj] = dist[p.first][p.second] + 1;
      qu.emplace(ni, nj);
    }
  }

  // debug(dist, H, W);
  return dist;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  ll N, M;
  cin >> N >> M;
  vl A(N), B(N), C(N), D(M), E(M), F(M);

  REP(i, N) cin >> A[i] >> B[i] >> C[i];
  REP(i, M) cin >> D[i] >> E[i] >> F[i];

  vector<ll> xs, ys;
  xs.push_back(0);
  ys.push_back(0);
  REP(i, N) {
    xs.push_back(A[i]);
    xs.push_back(B[i]);
    ys.push_back(C[i]);
  }
  REP(i, M) {
    xs.push_back(D[i]);
    ys.push_back(E[i]);
    ys.push_back(F[i]);
  }

  auto compress = [](vl &X) {
    map<ll, ll> mp;
    sort(X.begin(), X.end());
    X.erase(unique(X.begin(), X.end()), X.end());
    ll cnt = 0;
    for (auto x : X) {
      mp[x] = cnt;
      cnt++;
    }
    return mp;
  };

  auto mpx = compress(xs);
  auto mpy = compress(ys);

  ll Nx = mpx.size();
  ll Ny = mpy.size();

  const ll INF = (1ll << 60);
  vector<ll> Xs, Ys;

  Xs.push_back(INF);
  REP(i, Nx) {
    Xs.push_back(0);
    if (i != Nx - 1) {
      Xs.push_back(xs[i + 1] - xs[i]);
    }
  }
  Xs.push_back(INF);

  Ys.push_back(INF);
  REP(i, Ny) {
    Ys.push_back(0);
    if (i != Ny - 1) {
      Ys.push_back(ys[i + 1] - ys[i]);
    }
  }
  Ys.push_back(INF);

  // dump(xs)
  // dump(ys)
  // dump(Xs)
  // dump(Ys)

  ll H = Xs.size();
  ll W = Ys.size();

  vector<string> S(H);
  REP(i, H) { REP(j, W) S[i].push_back('.'); }

  REP(i, N) {
    ll h1 = 2 * mpx[A[i]] + 1;
    ll h2 = 2 * mpx[B[i]] + 1;
    ll w1 = 2 * mpy[C[i]] + 1;
    for (ll h = h1; h <= h2; h++) {
      S[h][w1] = '#';
    }
  }

  REP(i, M) {
    ll h1 = 2 * mpx[D[i]] + 1;
    ll w1 = 2 * mpy[E[i]] + 1;
    ll w2 = 2 * mpy[F[i]] + 1;
    for (ll w = w1; w <= w2; w++)
      S[h1][w] = '#';
  }

  S[2 * mpx[0] + 1][2 * mpy[0] + 1] = 'S';

  auto dist = grid_bfs(S, 'S', '#');

  // REP(i, H){
  //     cout << S[i] << endl;
  // }
  // cout << endl;
  // cout << dist << endl;

  ll res = 0;
  REP(i, H) {
    REP(j, W) {
      if (dist[i][j] >= 0) {
        if (i == 0 or i == H - 1 or j == 0 or j == W - 1) {
          cout << "INF" << endl;
          return 0;
        }
        res += Xs[i] * Ys[j];
      }
    }
  }
  cout << res << endl;

  return 0;
}

Error: 0

Fixed submission:

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

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<double, double> pdd;
typedef vector<ll> vl;
typedef vector<vector<ll>> vvl;
// typedef vector<vector<ll>> Graph;

const ll mod = 1e9 + 7;
// const ll mod = 998244353;

#define REP(i, n) for (ll i = 0; i < (ll)n; i++)
#define dump(x) cerr << #x << " = " << (x) << endl;
#define spa << " " <<
#define fi first
#define se second

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 (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

template <class S, class T>
ostream &operator<<(ostream &os, const pair<S, T> v) {
  os << "(" << v.first << ", " << v.second << ")";
  return os;
}
template <class T> ostream &operator<<(ostream &os, const vector<T> v) {
  for (int i = 0; i < (int)v.size(); i++) {
    if (i > 0) {
      os << " ";
    }
    os << v[i];
  }
  return os;
}
template <class T> ostream &operator<<(ostream &os, const vector<vector<T>> v) {
  for (int i = 0; i < (int)v.size(); i++) {
    if (i > 0) {
      os << endl;
    }
    os << v[i];
  }
  return os;
}

template <typename T> void debug(vector<vector<T>> &v, ll h, ll w) {
  for (ll i = 0; i < h; i++) {
    cerr << v[i][0];
    for (ll j = 1; j < w; j++)
      cerr spa v[i][j];
    cerr << endl;
  }
};
template <typename T> void debug(vector<T> &v, ll n) {
  if (n != 0)
    cerr << v[0];
  for (ll i = 1; i < n; i++)
    cerr spa v[i];
  cerr << endl;
};

vector<vector<int>> grid_bfs(const vector<string> &S, const char start,
                             const char wall) {
  // start 文字が入っているところから始まる多始点BFS
  // wall があるセルには入れない．この辺は適当に変更

  const int num_dir = 4;
  const int dx[] = {0, -1, 0, 1};
  const int dy[] = {1, 0, -1, 0};

  const int H = S.size();
  const int W = S[0].size();
  vector<vector<int>> dist(H, vector<int>(W, -1));
  queue<pair<int, int>> qu;

  // initialization
  for (int i = 0; i < H; i++) {
    for (int j = 0; j < W; j++) {
      if (S[i][j] == start) {
        qu.emplace(i, j);
        dist[i][j] = 0;
      }
    }
  }

  // BFS
  while (!qu.empty()) {
    auto p = qu.front();
    qu.pop();
    for (int idx = 0; idx < num_dir; idx++) {
      int ni = p.first + dx[idx];
      int nj = p.second + dy[idx];

      if (ni < 0 or nj < 0 or ni > H - 1 or nj > W - 1)
        continue;
      if (dist[ni][nj] != -1)
        continue;
      if (S[ni][nj] == wall)
        continue;

      dist[ni][nj] = dist[p.first][p.second] + 1;
      qu.emplace(ni, nj);
    }
  }

  // debug(dist, H, W);
  return dist;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  ll N, M;
  cin >> N >> M;
  vl A(N), B(N), C(N), D(M), E(M), F(M);

  REP(i, N) cin >> A[i] >> B[i] >> C[i];
  REP(i, M) cin >> D[i] >> E[i] >> F[i];

  vector<ll> xs, ys;
  xs.push_back(0);
  ys.push_back(0);
  REP(i, N) {
    xs.push_back(A[i]);
    xs.push_back(B[i]);
    ys.push_back(C[i]);
  }
  REP(i, M) {
    xs.push_back(D[i]);
    ys.push_back(E[i]);
    ys.push_back(F[i]);
  }

  auto compress = [](vl &X) {
    map<ll, ll> mp;
    sort(X.begin(), X.end());
    X.erase(unique(X.begin(), X.end()), X.end());
    ll cnt = 0;
    for (auto x : X) {
      mp[x] = cnt;
      cnt++;
    }
    return mp;
  };

  auto mpx = compress(xs);
  auto mpy = compress(ys);

  ll Nx = mpx.size();
  ll Ny = mpy.size();

  const ll INF = (1ll << 60);
  vector<ll> Xs, Ys;

  Xs.push_back(INF);
  REP(i, Nx) {
    Xs.push_back(0);
    if (i != Nx - 1) {
      Xs.push_back(xs[i + 1] - xs[i]);
    }
  }
  Xs.push_back(INF);

  Ys.push_back(INF);
  REP(i, Nx) {
    Ys.push_back(0);
    if (i != Ny - 1) {
      Ys.push_back(ys[i + 1] - ys[i]);
    }
  }
  Ys.push_back(INF);

  // dump(xs)
  // dump(ys)
  // dump(Xs)
  // dump(Ys)

  ll H = Xs.size();
  ll W = Ys.size();

  vector<string> S(H);
  REP(i, H) { REP(j, W) S[i].push_back('.'); }

  REP(i, N) {
    ll h1 = 2 * mpx[A[i]] + 1;
    ll h2 = 2 * mpx[B[i]] + 1;
    ll w1 = 2 * mpy[C[i]] + 1;
    for (ll h = h1; h <= h2; h++)
      S[h][w1] = '#';
  }

  REP(i, M) {
    ll h1 = 2 * mpx[D[i]] + 1;
    ll w1 = 2 * mpy[E[i]] + 1;
    ll w2 = 2 * mpy[F[i]] + 1;
    for (ll w = w1; w <= w2; w++)
      S[h1][w] = '#';
  }

  S[2 * mpx[0] + 1][2 * mpy[0] + 1] = 'S';

  auto dist = grid_bfs(S, 'S', '#');

  // REP(i, H){
  //     cout << S[i] << endl;
  // }
  // cout << endl;
  // cout << dist << endl;

  ll res = 0;
  REP(i, H) {
    REP(j, W) {
      if (dist[i][j] >= 0) {
        if (i == 0 or i == H - 1 or j == 0 or j == W - 1) {
          cout << "INF" << endl;
          return 0;
        }
        res += Xs[i] * Ys[j];
      }
    }
  }
  cout << res << endl;

  return 0;
}