Problem p01281 (C++)

Buggy submission (status: Runtime Error):
#define DEBUG_ON
#define CONDITION true
using namespace std; /*{{{*/

#include <algorithm>
#include <cassert>
#include <cctype>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <sys/time.h>
#include <vector>

#define INF (1e9)
static const double PI = acos(-1.0);
static const double EPS = 1e-10;

typedef long long int LL;
typedef unsigned long long int ULL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<double> VD;
typedef vector<VD> VVD;
typedef vector<char> VC;
typedef vector<VC> VVC;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef complex<double> P;

#define FOR(i, b, e) for (typeof(e) i = (b); i != (e); i < (e) ? ++i : --i)
#define REP(i, n) FOR(i, 0, n)

#define IFC(c)                                                                 \
  if (c)                                                                       \
    continue;
#define IFB(c)                                                                 \
  if (c)                                                                       \
    break;
#define IFR(c, r)                                                              \
  if (c)                                                                       \
    return r;

#define OPOVER(_op, _type) inline bool operator _op(const _type &t) const

#define arrsz(a) (sizeof(a) / sizeof(a[0]))

#define F first
#define S second
#define MP(a, b) make_pair(a, b)

#define SZ(a) ((LL)a.size())
#define PB(e) push_back(e)
#define SORT(v) sort((v).begin(), (v).end())
#define RSORT(v) sort((v).rbegin(), (v).rend())

#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EACH(c, it)                                                            \
  for (__typeof((c).begin()) it = (c).begin(); it != (c).end(); ++it)
#define EXIST(s, e) ((s).find(e) != (s).end())

#define BIT(n) (assert(n < 64), (1ULL << (n)))
#define BITOF(n, m) (assert(m < 64), ((ULL)(n) >> (m)&1))

#define RANGE(a, b, c) ((a) <= (b) && (b) <= (c))

#define PQ priority_queue
#define SC static_cast

#ifdef DEBUG_ON
#define dprt(fmt, ...)                                                         \
  if (CONDITION)                                                               \
  fprintf(stderr, fmt, ##__VA_ARGS__)
#define darr(a)                                                                \
  if (CONDITION)                                                               \
    copy((a), (a) + arrsz(a), ostream_iterator<int>(cerr, " "));               \
  cerr << endl
#define darr_range(a, f, t)                                                    \
  if (CONDITION)                                                               \
    copy((a) + (f), (a) + (t), ostream_iterator<int>(cerr, " "));              \
  cerr << endl
#define dvec(v)                                                                \
  if (CONDITION)                                                               \
    copy(ALL(v), ostream_iterator<int>(cerr, " "));                            \
  cerr << endl
#define darr2(a, n, m)                                                         \
  if (CONDITION)                                                               \
    FOR(i, 0, (n)) { darr_range((a)[i], 0, (m)); }
#define dvec2(v)                                                               \
  if (CONDITION)                                                               \
    FOR(i, 0, SZ(v)) { dvec((v)[i]); }
#define WAIT()                                                                 \
  if (CONDITION) {                                                             \
    string _wait_;                                                             \
    cerr << "(hit return to continue)" << endl;                                \
    getline(cin, _wait_);                                                      \
  }
#define dump(x)                                                                \
  if (CONDITION)                                                               \
    cerr << " [L" << __LINE__ << "] " << #x << " = " << (x) << endl;
#define dumpf()                                                                \
  if (CONDITION)                                                               \
    cerr << __PRETTY_FUNCTION__ << endl;
#define dumpv(x)                                                               \
  if (CONDITION)                                                               \
    cerr << " [L:" << __LINE__ << "] " << #x << " = ";                         \
  REP(q, (x).size()) cerr << (x)[q] << " ";                                    \
  cerr << endl;
#define where()                                                                \
  if (CONDITION)                                                               \
    cerr << __FILE__ << ": " << __PRETTY_FUNCTION__ << " [L: " << __LINE__     \
         << "]" << endl;
#define show_bits(b, s)                                                        \
  if (CONDITION) {                                                             \
    REP(i, s) {                                                                \
      cerr << BITOF(b, s - 1 - i);                                             \
      if (i % 4 == 3)                                                          \
        cerr << ' ';                                                           \
    }                                                                          \
    cerr << endl;                                                              \
  }
#else
#define cerr                                                                   \
  if (0)                                                                       \
  cerr
#define dprt(fmt, ...)
#define darr(a)
#define darr_range(a, f, t)
#define dvec(v)
#define darr2(a, n, m)
#define dvec2(v)
#define WAIT()
#define dump(x)
#define dumpf()
#define dumpv(x)
#define where()
#define show_bits(b, s)
#endif

/* Inline functions */
inline int onbits_count(ULL b) {
  int c = 0;
  while (b != 0) {
    c += (b & 1);
    b >>= 1;
  }
  return c;
}
inline int bits_count(ULL b) {
  int c = 0;
  while (b != 0) {
    ++c;
    b >>= 1;
  }
  return c;
}
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}
inline double now() {
  struct timeval tv;
  gettimeofday(&tv, NULL);
  return (static_cast<double>(tv.tv_sec) +
          static_cast<double>(tv.tv_usec) * 1e-6);
}
inline VS split(string s, char delimiter) {
  VS v;
  string t;
  REP(i, s.length()) {
    if (s[i] == delimiter)
      v.PB(t), t = "";
    else
      t += s[i];
  }
  v.PB(t);
  return v;
}

/* Tweaks */
template <typename T1, typename T2>
ostream &operator<<(ostream &s, const pair<T1, T2> &d) {
  return s << "(" << d.first << ", " << d.second << ")";
}

/* Frequent stuffs */
int n_dir = 4;
int dx[] = {0, 1, 0, -1}, dy[] = {-1, 0, 1, 0}; /* CSS order */
enum direction { UP, RIGHT, DOWN, LEFT };
// int n_dir = 8;
// int dx[] = {0, 1, 1, 1, 0, -1, -1, -1}, dy[] = {-1, -1, 0, 1, 1, 1, 0, -1};
// enum direction {
// UP, UPRIGHT, RIGHT, DOWNRIGHT, DOWN, DOWNLEFT, LEFT, UPLEFT
// }
#define FORDIR(d) REP(d, n_dir)

/*}}}*/

enum state { EMPTY, HL, HR, VT, VB };
vector<vector<state>> field;
int H, W;

int rec(int i, int j) {
  if (i == H) {
    return 1;
  }
  if (j >= W) {
    return rec(i + 1, 0);
  }
  if (field[i][j] != EMPTY) {
    return rec(i, j + 1);
  }

  REP(y, H) {
    REP(x, W) { cerr << field[y][x] << " "; }
    cerr << endl;
  }

  int ret = 0;
  // horizontal
  if (i - 1 < 0 || j - 1 < 0 || field[i - 1][j - 1] == HL ||
      field[i - 1][j - 1] == VT) {
    if (i - 1 < 0 || j + 2 == W || field[i - 1][j + 2] == HR ||
        field[i - 1][j + 2] == VT) {
      if (j + 1 < W && field[i][j + 1] == EMPTY) {
        field[i][j] = HL, field[i][j + 1] = HR;
        ret += rec(i, j + 1);
        field[i][j] = EMPTY, field[i][j + 1] = EMPTY;
      }
    }
  }
  // vertical
  if (i - 1 < 0 || j - 1 < 0 || field[i - 1][j - 1] == HL ||
      field[i - 1][j - 1] == VT) {
    if (i - 1 < 0 || j + 1 == W || field[i - 1][j + 1] == HR ||
        field[i - 1][j + 1] == VT) {
      if (i + 1 < H) {
        field[i][j] = VT, field[i + 1][j] = VB;
        ret += rec(i, j + 1);
        field[i][j] = EMPTY, field[i + 1][j] = EMPTY;
      }
    }
  }
  return ret;
}

int main() {
  std::ios_base::sync_with_stdio(false);
  while (cin >> H >> W, H | W) {
    field = vector<vector<state>>(H, vector<state>(W, EMPTY));
    cout << rec(0, 0) << endl;
  }
}

// vim: foldmethod=marker

Fixed submission:
#define DEBUG_ON
#define CONDITION true
using namespace std; /*{{{*/

#include <algorithm>
#include <cassert>
#include <cctype>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <sys/time.h>
#include <vector>

#define INF (1e9)
static const double PI = acos(-1.0);
static const double EPS = 1e-10;

typedef long long int LL;
typedef unsigned long long int ULL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<double> VD;
typedef vector<VD> VVD;
typedef vector<char> VC;
typedef vector<VC> VVC;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef complex<double> P;

#define FOR(i, b, e) for (typeof(e) i = (b); i != (e); i < (e) ? ++i : --i)
#define REP(i, n) FOR(i, 0, n)

#define IFC(c)                                                                 \
  if (c)                                                                       \
    continue;
#define IFB(c)                                                                 \
  if (c)                                                                       \
    break;
#define IFR(c, r)                                                              \
  if (c)                                                                       \
    return r;

#define OPOVER(_op, _type) inline bool operator _op(const _type &t) const

#define arrsz(a) (sizeof(a) / sizeof(a[0]))

#define F first
#define S second
#define MP(a, b) make_pair(a, b)

#define SZ(a) ((LL)a.size())
#define PB(e) push_back(e)
#define SORT(v) sort((v).begin(), (v).end())
#define RSORT(v) sort((v).rbegin(), (v).rend())

#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EACH(c, it)                                                            \
  for (__typeof((c).begin()) it = (c).begin(); it != (c).end(); ++it)
#define EXIST(s, e) ((s).find(e) != (s).end())

#define BIT(n) (assert(n < 64), (1ULL << (n)))
#define BITOF(n, m) (assert(m < 64), ((ULL)(n) >> (m)&1))

#define RANGE(a, b, c) ((a) <= (b) && (b) <= (c))

#define PQ priority_queue
#define SC static_cast

#ifdef DEBUG_ON
#define dprt(fmt, ...)                                                         \
  if (CONDITION)                                                               \
  fprintf(stderr, fmt, ##__VA_ARGS__)
#define darr(a)                                                                \
  if (CONDITION)                                                               \
    copy((a), (a) + arrsz(a), ostream_iterator<int>(cerr, " "));               \
  cerr << endl
#define darr_range(a, f, t)                                                    \
  if (CONDITION)                                                               \
    copy((a) + (f), (a) + (t), ostream_iterator<int>(cerr, " "));              \
  cerr << endl
#define dvec(v)                                                                \
  if (CONDITION)                                                               \
    copy(ALL(v), ostream_iterator<int>(cerr, " "));                            \
  cerr << endl
#define darr2(a, n, m)                                                         \
  if (CONDITION)                                                               \
    FOR(i, 0, (n)) { darr_range((a)[i], 0, (m)); }
#define dvec2(v)                                                               \
  if (CONDITION)                                                               \
    FOR(i, 0, SZ(v)) { dvec((v)[i]); }
#define WAIT()                                                                 \
  if (CONDITION) {                                                             \
    string _wait_;                                                             \
    cerr << "(hit return to continue)" << endl;                                \
    getline(cin, _wait_);                                                      \
  }
#define dump(x)                                                                \
  if (CONDITION)                                                               \
    cerr << " [L" << __LINE__ << "] " << #x << " = " << (x) << endl;
#define dumpf()                                                                \
  if (CONDITION)                                                               \
    cerr << __PRETTY_FUNCTION__ << endl;
#define dumpv(x)                                                               \
  if (CONDITION)                                                               \
    cerr << " [L:" << __LINE__ << "] " << #x << " = ";                         \
  REP(q, (x).size()) cerr << (x)[q] << " ";                                    \
  cerr << endl;
#define where()                                                                \
  if (CONDITION)                                                               \
    cerr << __FILE__ << ": " << __PRETTY_FUNCTION__ << " [L: " << __LINE__     \
         << "]" << endl;
#define show_bits(b, s)                                                        \
  if (CONDITION) {                                                             \
    REP(i, s) {                                                                \
      cerr << BITOF(b, s - 1 - i);                                             \
      if (i % 4 == 3)                                                          \
        cerr << ' ';                                                           \
    }                                                                          \
    cerr << endl;                                                              \
  }
#else
#define cerr                                                                   \
  if (0)                                                                       \
  cerr
#define dprt(fmt, ...)
#define darr(a)
#define darr_range(a, f, t)
#define dvec(v)
#define darr2(a, n, m)
#define dvec2(v)
#define WAIT()
#define dump(x)
#define dumpf()
#define dumpv(x)
#define where()
#define show_bits(b, s)
#endif

/* Inline functions */
inline int onbits_count(ULL b) {
  int c = 0;
  while (b != 0) {
    c += (b & 1);
    b >>= 1;
  }
  return c;
}
inline int bits_count(ULL b) {
  int c = 0;
  while (b != 0) {
    ++c;
    b >>= 1;
  }
  return c;
}
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}
inline double now() {
  struct timeval tv;
  gettimeofday(&tv, NULL);
  return (static_cast<double>(tv.tv_sec) +
          static_cast<double>(tv.tv_usec) * 1e-6);
}
inline VS split(string s, char delimiter) {
  VS v;
  string t;
  REP(i, s.length()) {
    if (s[i] == delimiter)
      v.PB(t), t = "";
    else
      t += s[i];
  }
  v.PB(t);
  return v;
}

/* Tweaks */
template <typename T1, typename T2>
ostream &operator<<(ostream &s, const pair<T1, T2> &d) {
  return s << "(" << d.first << ", " << d.second << ")";
}

/* Frequent stuffs */
int n_dir = 4;
int dx[] = {0, 1, 0, -1}, dy[] = {-1, 0, 1, 0}; /* CSS order */
enum direction { UP, RIGHT, DOWN, LEFT };
// int n_dir = 8;
// int dx[] = {0, 1, 1, 1, 0, -1, -1, -1}, dy[] = {-1, -1, 0, 1, 1, 1, 0, -1};
// enum direction {
// UP, UPRIGHT, RIGHT, DOWNRIGHT, DOWN, DOWNLEFT, LEFT, UPLEFT
// }
#define FORDIR(d) REP(d, n_dir)

/*}}}*/

enum state { EMPTY, HL, HR, VT, VB };
vector<vector<state>> field;
int H, W;

int rec(int i, int j) {
  if (i == H) {
    return 1;
  }
  if (j >= W) {
    return rec(i + 1, 0);
  }
  if (field[i][j] != EMPTY) {
    return rec(i, j + 1);
  }

  // REP (y, H) {
  // REP (x, W) {
  // cerr << field[y][x] << " ";
  // }
  // cerr << endl;
  // }

  int ret = 0;
  // horizontal
  if (i - 1 < 0 || j - 1 < 0 || field[i - 1][j - 1] == HL ||
      field[i - 1][j - 1] == VT) {
    if (i - 1 < 0 || j + 2 == W || field[i - 1][j + 2] == HR ||
        field[i - 1][j + 2] == VT) {
      if (j + 1 < W && field[i][j + 1] == EMPTY) {
        field[i][j] = HL, field[i][j + 1] = HR;
        ret += rec(i, j + 1);
        field[i][j] = EMPTY, field[i][j + 1] = EMPTY;
      }
    }
  }
  // vertical
  if (i - 1 < 0 || j - 1 < 0 || field[i - 1][j - 1] == HL ||
      field[i - 1][j - 1] == VT) {
    if (i - 1 < 0 || j + 1 == W || field[i - 1][j + 1] == HR ||
        field[i - 1][j + 1] == VT) {
      if (i + 1 < H) {
        field[i][j] = VT, field[i + 1][j] = VB;
        ret += rec(i, j + 1);
        field[i][j] = EMPTY, field[i + 1][j] = EMPTY;
      }
    }
  }
  return ret;
}

int main() {
  std::ios_base::sync_with_stdio(false);
  while (cin >> H >> W, H | W) {
    field = vector<vector<state>>(H, vector<state>(W, EMPTY));
    cout << rec(0, 0) << endl;
  }
}

// vim: foldmethod=marker