Problem p03014 (C++)

Buggy submission (status: Runtime Error):
#include "bits/stdc++.h"
using namespace std;
#define int long long // <-----!!!!!!!!!!!!!!!!!!!

#define rep(i, n) for (int i = 0; i < (n); i++)
#define rep2(i, a, b) for (int i = (a); i < (b); i++)
#define rrep(i, n) for (int i = (n)-1; i >= 0; i--)
#define rrep2(i, a, b) for (int i = (a)-1; i >= b; i--)
#define chmin(a, b) (a) = min((a), (b));
#define chmax(a, b) (a) = max((a), (b));
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define printV(v)                                                              \
  cerr << (#v) << ":";                                                         \
  for (auto(x) : (v)) {                                                        \
    cerr << " " << (x);                                                        \
  }                                                                            \
  cerr << endl;
#define printVS(vs)                                                            \
  cerr << (#vs) << ":" << endl;                                                \
  for (auto(s) : (vs)) {                                                       \
    cerr << (s) << endl;                                                       \
  }
#define printVV(vv)                                                            \
  cerr << (#vv) << ":" << endl;                                                \
  for (auto(v) : (vv)) {                                                       \
    for (auto(x) : (v)) {                                                      \
      cerr << " " << (x);                                                      \
    }                                                                          \
    cerr << endl;                                                              \
  }
#define printP(p) cerr << (#p) << (p).first << " " << (p).second << endl;
#define printVP(vp)                                                            \
  cerr << (#vp) << ":" << endl;                                                \
  for (auto(p) : (vp)) {                                                       \
    cerr << (p).first << " " << (p).second << endl;                            \
  }

inline void output() { cerr << endl; }
template <typename First, typename... Rest>
inline void output(const First &first, const Rest &...rest) {
  cerr << first << " ";
  output(rest...);
}

using ll = long long;
using Pii = pair<int, int>;
using TUPLE = tuple<int, int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
const int inf = 1ll << 60;
const int mod = 1e9 + 7;
using Graph = vector<vector<int>>;

int d[2000][2000][4];

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

  int h, w;
  cin >> h >> w;
  int H = h + 2;
  int W = w + 2;
  vector<string> s(H);
  s[0] = string(W, '#');
  rep(i, h) {
    int r = i + 1;
    cin >> s[r];
    s[r] = '#' + s[r] + '#';
  }
  s[H - 1] = string(W, '#');

  rep(r, H) {
    rep(c, W) {
      if (s[r][c] == '#') {
        d[r][c][0] = -1;
      } else {
        d[r][c][0] = d[r][c - 1][0] + 1;
      }
    }
  }

  rep(r, H) {
    rrep(c, W) {
      if (s[r][c] == '#') {
        d[r][c][1] = -1;
      } else {
        d[r][c][1] = d[r][c + 1][1] + 1;
      }
    }
  }

  rep(c, W) {
    rep(r, H) {
      if (s[r][c] == '#') {
        d[r][c][2] = -1;
      } else {
        d[r][c][2] = d[r - 1][c][2] + 1;
      }
    }
  }

  rep(c, W) {
    rrep(r, H) {
      if (s[r][c] == '#') {
        d[r][c][3] = -1;
      } else {
        d[r][c][3] = d[r + 1][c][3] + 1;
      }
    }
  }

  int ma = 0;
  rep(r, H) {
    rep(c, W) {
      if (s[r][c] == '.') {
        chmax(ma, d[r][c][0] + d[r][c][1] + d[r][c][2] + d[r][c][3] + 1);
      }
    }
  }

  cout << ma << endl;
}


Fixed submission:
#include "bits/stdc++.h"
using namespace std;
#define int long long // <-----!!!!!!!!!!!!!!!!!!!

#define rep(i, n) for (int i = 0; i < (n); i++)
#define rep2(i, a, b) for (int i = (a); i < (b); i++)
#define rrep(i, n) for (int i = (n)-1; i >= 0; i--)
#define rrep2(i, a, b) for (int i = (a)-1; i >= b; i--)
#define chmin(a, b) (a) = min((a), (b));
#define chmax(a, b) (a) = max((a), (b));
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define printV(v)                                                              \
  cerr << (#v) << ":";                                                         \
  for (auto(x) : (v)) {                                                        \
    cerr << " " << (x);                                                        \
  }                                                                            \
  cerr << endl;
#define printVS(vs)                                                            \
  cerr << (#vs) << ":" << endl;                                                \
  for (auto(s) : (vs)) {                                                       \
    cerr << (s) << endl;                                                       \
  }
#define printVV(vv)                                                            \
  cerr << (#vv) << ":" << endl;                                                \
  for (auto(v) : (vv)) {                                                       \
    for (auto(x) : (v)) {                                                      \
      cerr << " " << (x);                                                      \
    }                                                                          \
    cerr << endl;                                                              \
  }
#define printP(p) cerr << (#p) << (p).first << " " << (p).second << endl;
#define printVP(vp)                                                            \
  cerr << (#vp) << ":" << endl;                                                \
  for (auto(p) : (vp)) {                                                       \
    cerr << (p).first << " " << (p).second << endl;                            \
  }

inline void output() { cerr << endl; }
template <typename First, typename... Rest>
inline void output(const First &first, const Rest &...rest) {
  cerr << first << " ";
  output(rest...);
}

using ll = long long;
using Pii = pair<int, int>;
using TUPLE = tuple<int, int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
const int inf = 1ll << 60;
const int mod = 1e9 + 7;
using Graph = vector<vector<int>>;

int d[2002][2002][4];

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

  int h, w;
  cin >> h >> w;
  int H = h + 2;
  int W = w + 2;
  vector<string> s(H);
  s[0] = string(W, '#');
  rep(i, h) {
    int r = i + 1;
    cin >> s[r];
    s[r] = '#' + s[r] + '#';
  }
  s[H - 1] = string(W, '#');

  rep(r, H) {
    rep(c, W) {
      if (s[r][c] == '#') {
        d[r][c][0] = -1;
      } else {
        d[r][c][0] = d[r][c - 1][0] + 1;
      }
    }
  }

  rep(r, H) {
    rrep(c, W) {
      if (s[r][c] == '#') {
        d[r][c][1] = -1;
      } else {
        d[r][c][1] = d[r][c + 1][1] + 1;
      }
    }
  }

  rep(c, W) {
    rep(r, H) {
      if (s[r][c] == '#') {
        d[r][c][2] = -1;
      } else {
        d[r][c][2] = d[r - 1][c][2] + 1;
      }
    }
  }

  rep(c, W) {
    rrep(r, H) {
      if (s[r][c] == '#') {
        d[r][c][3] = -1;
      } else {
        d[r][c][3] = d[r + 1][c][3] + 1;
      }
    }
  }

  int ma = 0;
  rep(r, H) {
    rep(c, W) {
      if (s[r][c] == '.') {
        chmax(ma, d[r][c][0] + d[r][c][1] + d[r][c][2] + d[r][c][3] + 1);
      }
    }
  }

  cout << ma << endl;
}