Problem p00923 (C++) — buggy submission, verdict: Runtime Error

// very kuso problem

#include <algorithm> // other
#include <bitset>
#include <cassert> // c
#include <complex>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream> // io
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <regex>
#include <set>
#include <sstream>
#include <stack>
#include <vector> // container
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

#define ALL(c) c.begin(), c.end()
#define IN(l, v, r) (l <= v && v < r)
template <class T> void UNIQUE(T &v) {
  sort(ALL(v));
  v.erase(unique(ALL(v)), v.end());
}

#define DUMP(x) cerr << #x << " = " << (x)
#define LINE() cerr << " (L" << __LINE__ << ")"

#define range(i, l, r) for (int i = (int)l; i < (int)(r); i++)
// struct range{
// 	struct Iter{
// 		int v,step;
// 		Iter& operator++(){v+=step;return *this;}
// 		bool operator!=(Iter& itr){return v<itr.v;}
// 		int& operator*(){return v;}
// 	};
// 	Iter i, n;
// 	range(int i, int n,int step):i({i,step}), n({n,step}){}
// 	range(int i, int n):range(i,n,1){}
// 	range(int n):range(0,n){}
// 	Iter& begin(){return i;}
// 	Iter& end(){return n;}
// };

// input
template <typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) {
  return is >> p.first >> p.second;
}
template <typename T1> istream &operator>>(istream &is, tuple<T1> &t) {
  return is >> get<0>(t);
}
template <typename T1, typename T2>
istream &operator>>(istream &is, tuple<T1, T2> &t) {
  return is >> get<0>(t) >> get<1>(t);
}
template <typename T1, typename T2, typename T3>
istream &operator>>(istream &is, tuple<T1, T2, T3> &t) {
  return is >> get<0>(t) >> get<1>(t) >> get<2>(t);
}
template <typename T1, typename T2, typename T3, typename T4>
istream &operator>>(istream &is, tuple<T1, T2, T3, T4> &t) {
  return is >> get<0>(t) >> get<1>(t) >> get<2>(t) >> get<3>(t);
}
template <typename T> istream &operator>>(istream &is, vector<T> &as) {
  range(i, 0, as.size()) is >> as[i];
  return is;
}
// output
template <typename T> ostream &operator<<(ostream &os, const set<T> &ss) {
  for (auto a : ss) {
    if (a != ss.begin())
      os << " ";
    os << a;
  }
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  return os << p.first << " " << p.second;
}
template <typename K, typename V>
ostream &operator<<(ostream &os, const map<K, V> &m) {
  bool isF = true;
  for (auto &p : m) {
    if (!isF)
      os << endl;
    os << p;
    isF = false;
  }
  return os;
}
template <typename T1> ostream &operator<<(ostream &os, const tuple<T1> &t) {
  return os << get<0>(t);
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const tuple<T1, T2> &t) {
  return os << get<0>(t) << " " << get<1>(t);
}
template <typename T1, typename T2, typename T3>
ostream &operator<<(ostream &os, const tuple<T1, T2, T3> &t) {
  return os << get<0>(t) << " " << get<1>(t) << " " << get<2>(t);
}
template <typename T1, typename T2, typename T3, typename T4>
ostream &operator<<(ostream &os, const tuple<T1, T2, T3, T4> &t) {
  return os << get<0>(t) << " " << get<1>(t) << " " << get<2>(t) << " "
            << get<3>(t);
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &as) {
  range(i, 0, as.size()) {
    if (i != 0)
      os << " ";
    os << as[i];
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<vector<T>> &as) {
  range(i, 0, as.size()) {
    if (i != 0)
      os << endl;
    os << as[i];
  }
  return os;
}

struct Edge {
  char c;
  int f, t;
};

class NFA {
public:
  static NFA ONE;
  int N;
  vector<Edge> es;
  vector<vector<int>> f_cache, t_cache;

  vector<vector<int>> reachable;
  vector<vector<vector<int>>> trans;

  int s, t;
  NFA(int N = 0) : N(N), s(0), t(1) {
    f_cache = t_cache = vector<vector<int>>(N);
  }
  void add_edge(char c, int f, int t) {
    int eid = es.size();
    es.push_back({c, f, t});
    f_cache[f].push_back(eid);
    t_cache[t].push_back(eid);
  }
  static NFA *disjoint(NFA *a, NFA *b) {
    // merge technique
    NFA *res = (a->es.size() < b->es.size() ? b : a),
        *add = (a->es.size() < b->es.size() ? a : b);
    res->f_cache.resize(res->N + add->N);
    res->t_cache.resize(res->N + add->N);
    int eid = res->es.size();
    for (Edge &e : add->es) {
      e.f += res->N;
      e.t += res->N;
      res->es.push_back(e);
      res->f_cache[e.f].push_back(eid);
      res->t_cache[e.t].push_back(eid);
      eid++;
    }
    res->N += add->N;
    return res;
  }
  static NFA *Union(NFA *a, NFA *b) {
    bool bl = a->es.size() < b->es.size();
    int as = (bl ? b->N : 0) + a->s, at = (bl ? b->N : 0) + a->t,
        bs = (!bl ? a->N : 0) + b->s, bt = (!bl ? a->N : 0) + b->t;
    int S = a->N + b->N, T = a->N + b->N + 1;
    NFA *ab = disjoint(a, b), *ab1 = disjoint(ab, &ONE),
        *res = disjoint(ab1, &ONE);
    res->add_edge('-', S, as);
    res->add_edge('-', S, bs);
    res->add_edge('-', at, T);
    res->add_edge('-', bt, T);
    res->s = S;
    res->t = T;
    return res;
  }
  static NFA *Concat(NFA *a, NFA *b) {
    bool bl = a->es.size() < b->es.size();
    int as = (bl ? b->N : 0) + a->s, at = (bl ? b->N : 0) + a->t,
        bs = (!bl ? a->N : 0) + b->s, bt = (!bl ? a->N : 0) + b->t;
    NFA *res = disjoint(a, b);
    res->add_edge('-', at, bs);
    res->s = as;
    res->t = bt;
    return res;
  }
  static NFA *Star(NFA *a) {
    NFA *res = disjoint(a, &ONE);
    res->add_edge('-', res->N - 1, a->s);
    res->add_edge('-', a->t, res->N - 1);
    res->s = res->t = res->N - 1;
    return res;
  }

  // step
  void create_reachable() {
    queue<pair<int, int>> que;
    que.push({t, 0});

    reachable = vector<vector<int>>(N, vector<int>(4));
    reachable[t][0] = true;
    while (!que.empty()) {
      int t, d;
      tie(t, d) = que.front();
      que.pop();
      // back
      for (int eid : t_cache[t]) {
        Edge &e = es[eid];
        if (e.c == '-') {
          if (!reachable[e.f][d]) {
            reachable[e.f][d] = true;
            que.push({e.f, d});
          }
        } else {
          if (d + 1 < reachable[e.f].size() && !reachable[e.f][d + 1]) {
            reachable[e.f][d + 1] = true;
            que.push({e.f, d + 1});
          }
        }
      }
    }
  }

  void create_trans() {
    trans = vector<vector<vector<int>>>(N, vector<vector<int>>(27));
    // eps trans
    range(st, 0, N) {
      vector<bool> passed(N);
      passed[st] = true;
      queue<int> que;
      range(i, 0, passed.size()) if (passed[i]) que.push(i);
      while (!que.empty()) {
        int s = que.front();
        que.pop();
        for (int eid : f_cache[s])
          if (es[eid].c == '-' && !passed[es[eid].t]) {
            passed[es[eid].t] = true;
            que.push(es[eid].t);
          }
      }
      range(i, 0, N) if (passed[i]) trans[st][26].push_back(i);
    }
    range(st, 0, N) range(c, 'A', 'Z' + 1) {
      // eps trans
      vector<bool> passed(N);
      for (int s : trans[st][26])
        passed[s] = true;
      vector<bool> npassed(N);
      queue<int> que;
      range(i, 0, passed.size()) if (passed[i]) que.push(i);
      while (!que.empty()) {
        int s = que.front();
        que.pop();
        for (int eid : f_cache[s])
          if ((es[eid].c == c || es[eid].c == '.') && !npassed[es[eid].t]) {
            npassed[es[eid].t] = true;
            que.push(es[eid].t);
          }
      }
      // eps trans
      range(i, 0, N) if (npassed[i]) for (int s : trans[i][26]) npassed[s] =
          true;
      range(s, 0, npassed.size()) if (npassed[s]) {
        bool alleps = true;
        for (int eid : f_cache[s])
          alleps &= es[eid].c == '-';
        // ???????????? ?? ????§???????????????´?????????????????? for ?????????
        if (alleps && t != s)
          continue;
        trans[st][c - 'A'].push_back(s);
      }
    }
  }
} NFA::ONE = NFA(1);

class REGtoNFA {
public:
  static NFA *pattern(string &s, int &i, int e) {
    NFA *p = simple(s, i, e);
    while (i < e && s[i] == '|') {
      i++; // '|'
      NFA *q = simple(s, i, e);
      p = NFA::Union(p, q);
    }
    return p;
  }
  static NFA *simple(string &s, int &i, int e) {
    NFA *p = basic(s, i, e);
    while (i < e && s[i] != '|') {
      NFA *q = basic(s, i, e);
      p = NFA::Concat(p, q);
    }
    return p;
  }
  static NFA *basic(string &s, int &i, int e) {
    NFA *p = elementary(s, i, e);
    if (i < (int)s.size() && s[i] == '*') {
      i++; // *
      p = NFA::Star(p);
    }
    return p;
  }
  static NFA *elementary(string &s, int &i, int e) {
    NFA *p;
    if (s[i] == '(') {
      i++; // (
      int d = 1;
      for (int j = i; j < e; j++) {
        if (s[j] == '(')
          d++;
        if (s[j] == ')')
          d--;
        if (d == 0) {
          e = j;
          break;
        }
      }
      p = pattern(s, i, e);
      i++; // )
    } else {
      p = new NFA(2);
      p->add_edge(s[i], p->s, p->t);
      i++; // c
    }
    return p;
  }
};

int rc = 0;
class Main {
public:
  int h, w;
  vector<string> tmp, res;

  vector<NFA> NFAs;
  vector<vector<int>> stats;

  void dfs(int y, int x, int c) {
    if (rc > 1)
      return;
    if (y == h) {
      rc += c;
      res = tmp;
      return;
    }
    // ????????????????????¶??????????????´????????????????????????????????¢?´¢
    vector<vector<vector<int>>> nstats(2, vector<vector<int>>(26));
    vector<int> nfai = {y, h + x};
    range(ni, 0, 2) for (char nc = 'A'; nc <= 'Z'; nc++) {
      for (int s : stats[nfai[ni]])
        for (int t : NFAs[nfai[ni]].trans[s][nc - 'A'])
          nstats[ni][nc - 'A'].push_back(t);
      UNIQUE(nstats[ni][nc - 'A']);
    }
    vector<int> gid(26);
    iota(ALL(gid), 0);
    for (char c1 = 'A'; c1 <= 'Z'; c1++)
      for (char c2 = 'A'; c2 < c1; c2++)
        if (gid[c2 - 'A'] == c2 - 'A') {
          if (nstats[0][c1 - 'A'].size() == nstats[0][c2 - 'A'].size() &&
              nstats[1][c1 - 'A'].size() == nstats[1][c2 - 'A'].size()) {
            bool eq = true;
            range(ni, 0, 2) {
              range(i, 0, nstats[ni][c1 - 'A'].size()) {
                eq &= nstats[ni][c1 - 'A'][i] == nstats[ni][c2 - 'A'][i];
                if (!eq)
                  break;
              }
              if (!eq)
                break;
            }
            if (eq) {
              gid[c1 - 'A'] = gid[c2 - 'A'];
              break;
            }
          }
        }
    vector<int> gc(26);
    range(i, 0, 26) gc[gid[i]]++;

    for (char c = 'A'; c <= 'Z'; c++)
      if (gid[c - 'A'] == c - 'A') {
        tmp[y][x] = c;
        bool tmpOK = true;
        // eda ??????????????? de ikerukana ?
        {
          bool ok = false;
          for (int s : nstats[0][c - 'A'])
            ok |= NFAs[y].reachable[s][w - 1 - x];
          tmpOK &= ok;
        }
        {
          bool ok = false;
          for (int s : nstats[1][c - 'A'])
            ok |= NFAs[h + x].reachable[s][h - 1 - y];
          tmpOK &= ok;
        }
        if (x == w - 1) {
          bool ok = false;
          for (int s : nstats[0][c - 'A'])
            ok |= s == NFAs[y].t;
          tmpOK &= ok;
        }
        if (y == h - 1) {
          bool ok = false;
          for (int s : nstats[1][c - 'A'])
            ok |= s == NFAs[h + x].t;
          tmpOK &= ok;
        }
        if (tmpOK) {
          vector<int> tmpp = stats[y], tmpq = stats[h + x];
          stats[y] = nstats[0][c - 'A'];
          stats[h + x] = nstats[1][c - 'A'];
          if (x + 1 < w)
            dfs(y, x + 1, gc[c - 'A']);
          else
            dfs(y + 1, 0, gc[c - 'A']);
          stats[y] = tmpp;
          stats[h + x] = tmpq;
        }
      }
  }

  void run() {
    while (true) {
      cin >> h >> w;
      if (h == 0 && w == 0)
        break;
      rc = 0;
      tmp = res = vector<string>(h, string(w, '-'));
      vector<string> ss(h + w);
      cin >> ss;
      // h <= 4, w <= 4
      NFAs = vector<NFA>(h + w);
      range(i, 0, h + w) {
        string s = "";
        range(j, 1, ss[i].size() - 1) s += ss[i][j];
        int cur = 0, e = s.size();
        NFAs[i] = *REGtoNFA::pattern(s, cur, e);
      }
      range(i, 0, h + w) {
        NFAs[i].create_reachable();
        NFAs[i].create_trans();
      }
      stats = vector<vector<int>>(h + w);
      range(i, 0, h + w) stats[i].push_back(NFAs[i].s);

      dfs(0, 0, 1);
      if (rc > 1) {
        cout << "ambiguous" << endl;
      } else if (rc == 0) {
        cout << "none" << endl;
      } else {
        range(i, 0, h) cout << res[i] << endl;
      }
    }
  }
};

int main() {
  cout << fixed << setprecision(20);
  cin.tie(0);
  ios::sync_with_stdio(false);
  Main().run();
  return 0;
}

Error: TLE

Fixed submission:

// very kuso problem

#include <algorithm> // other
#include <bitset>
#include <cassert> // c
#include <complex>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream> // io
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <regex>
#include <set>
#include <sstream>
#include <stack>
#include <vector> // container
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

#define ALL(c) c.begin(), c.end()
#define IN(l, v, r) (l <= v && v < r)
template <class T> void UNIQUE(T &v) {
  sort(ALL(v));
  v.erase(unique(ALL(v)), v.end());
}

#define DUMP(x) cerr << #x << " = " << (x)
#define LINE() cerr << " (L" << __LINE__ << ")"

#define range(i, l, r) for (int i = (int)l; i < (int)(r); i++)
// struct range{
// 	struct Iter{
// 		int v,step;
// 		Iter& operator++(){v+=step;return *this;}
// 		bool operator!=(Iter& itr){return v<itr.v;}
// 		int& operator*(){return v;}
// 	};
// 	Iter i, n;
// 	range(int i, int n,int step):i({i,step}), n({n,step}){}
// 	range(int i, int n):range(i,n,1){}
// 	range(int n):range(0,n){}
// 	Iter& begin(){return i;}
// 	Iter& end(){return n;}
// };

// input
template <typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) {
  return is >> p.first >> p.second;
}
template <typename T1> istream &operator>>(istream &is, tuple<T1> &t) {
  return is >> get<0>(t);
}
template <typename T1, typename T2>
istream &operator>>(istream &is, tuple<T1, T2> &t) {
  return is >> get<0>(t) >> get<1>(t);
}
template <typename T1, typename T2, typename T3>
istream &operator>>(istream &is, tuple<T1, T2, T3> &t) {
  return is >> get<0>(t) >> get<1>(t) >> get<2>(t);
}
template <typename T1, typename T2, typename T3, typename T4>
istream &operator>>(istream &is, tuple<T1, T2, T3, T4> &t) {
  return is >> get<0>(t) >> get<1>(t) >> get<2>(t) >> get<3>(t);
}
template <typename T> istream &operator>>(istream &is, vector<T> &as) {
  range(i, 0, as.size()) is >> as[i];
  return is;
}
// output
template <typename T> ostream &operator<<(ostream &os, const set<T> &ss) {
  for (auto a : ss) {
    if (a != ss.begin())
      os << " ";
    os << a;
  }
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  return os << p.first << " " << p.second;
}
template <typename K, typename V>
ostream &operator<<(ostream &os, const map<K, V> &m) {
  bool isF = true;
  for (auto &p : m) {
    if (!isF)
      os << endl;
    os << p;
    isF = false;
  }
  return os;
}
template <typename T1> ostream &operator<<(ostream &os, const tuple<T1> &t) {
  return os << get<0>(t);
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const tuple<T1, T2> &t) {
  return os << get<0>(t) << " " << get<1>(t);
}
template <typename T1, typename T2, typename T3>
ostream &operator<<(ostream &os, const tuple<T1, T2, T3> &t) {
  return os << get<0>(t) << " " << get<1>(t) << " " << get<2>(t);
}
template <typename T1, typename T2, typename T3, typename T4>
ostream &operator<<(ostream &os, const tuple<T1, T2, T3, T4> &t) {
  return os << get<0>(t) << " " << get<1>(t) << " " << get<2>(t) << " "
            << get<3>(t);
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &as) {
  range(i, 0, as.size()) {
    if (i != 0)
      os << " ";
    os << as[i];
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<vector<T>> &as) {
  range(i, 0, as.size()) {
    if (i != 0)
      os << endl;
    os << as[i];
  }
  return os;
}

struct Edge {
  char c;
  int f, t;
};

class NFA {
public:
  static NFA ONE;
  int N;
  vector<Edge> es;
  vector<vector<int>> f_cache, t_cache;

  vector<vector<int>> reachable;
  vector<vector<vector<int>>> trans;

  int s, t;
  NFA(int N = 0) : N(N), s(0), t(1) {
    f_cache = t_cache = vector<vector<int>>(N);
  }
  void add_edge(char c, int f, int t) {
    int eid = es.size();
    es.push_back({c, f, t});
    f_cache[f].push_back(eid);
    t_cache[t].push_back(eid);
  }
  static NFA *disjoint(NFA *a, NFA *b) {
    // merge technique
    NFA *res = (a->es.size() < b->es.size() ? b : a),
        *add = (a->es.size() < b->es.size() ? a : b);
    res->f_cache.resize(res->N + add->N);
    res->t_cache.resize(res->N + add->N);
    int eid = res->es.size();
    for (Edge &e : add->es) {
      e.f += res->N;
      e.t += res->N;
      res->es.push_back(e);
      res->f_cache[e.f].push_back(eid);
      res->t_cache[e.t].push_back(eid);
      eid++;
    }
    res->N += add->N;
    return res;
  }
  static NFA *Union(NFA *a, NFA *b) {
    bool bl = a->es.size() < b->es.size();
    int as = (bl ? b->N : 0) + a->s, at = (bl ? b->N : 0) + a->t,
        bs = (!bl ? a->N : 0) + b->s, bt = (!bl ? a->N : 0) + b->t;
    int S = a->N + b->N, T = a->N + b->N + 1;
    NFA *ab = disjoint(a, b), *ab1 = disjoint(ab, &ONE),
        *res = disjoint(ab1, &ONE);
    res->add_edge('-', S, as);
    res->add_edge('-', S, bs);
    res->add_edge('-', at, T);
    res->add_edge('-', bt, T);
    res->s = S;
    res->t = T;
    return res;
  }
  static NFA *Concat(NFA *a, NFA *b) {
    bool bl = a->es.size() < b->es.size();
    int as = (bl ? b->N : 0) + a->s, at = (bl ? b->N : 0) + a->t,
        bs = (!bl ? a->N : 0) + b->s, bt = (!bl ? a->N : 0) + b->t;
    NFA *res = disjoint(a, b);
    res->add_edge('-', at, bs);
    res->s = as;
    res->t = bt;
    return res;
  }
  static NFA *Star(NFA *a) {
    NFA *res = disjoint(a, &ONE);
    res->add_edge('-', res->N - 1, a->s);
    res->add_edge('-', a->t, res->N - 1);
    res->s = res->t = res->N - 1;
    return res;
  }

  // step
  void create_reachable() {
    queue<pair<int, int>> que;
    que.push({t, 0});

    reachable = vector<vector<int>>(N, vector<int>(4));
    reachable[t][0] = true;
    while (!que.empty()) {
      int t, d;
      tie(t, d) = que.front();
      que.pop();
      // back
      for (int eid : t_cache[t]) {
        Edge &e = es[eid];
        if (e.c == '-') {
          if (!reachable[e.f][d]) {
            reachable[e.f][d] = true;
            que.push({e.f, d});
          }
        } else {
          if (d + 1 < reachable[e.f].size() && !reachable[e.f][d + 1]) {
            reachable[e.f][d + 1] = true;
            que.push({e.f, d + 1});
          }
        }
      }
    }
  }

  void create_trans() {
    trans = vector<vector<vector<int>>>(N, vector<vector<int>>(27));
    // eps trans
    range(st, 0, N) {
      vector<bool> passed(N);
      passed[st] = true;
      queue<int> que;
      range(i, 0, passed.size()) if (passed[i]) que.push(i);
      while (!que.empty()) {
        int s = que.front();
        que.pop();
        for (int eid : f_cache[s])
          if (es[eid].c == '-' && !passed[es[eid].t]) {
            passed[es[eid].t] = true;
            que.push(es[eid].t);
          }
      }
      range(i, 0, N) if (passed[i]) trans[st][26].push_back(i);
    }
    range(st, 0, N) range(c, 'A', 'Z' + 1) {
      // eps trans
      vector<bool> passed(N);
      for (int s : trans[st][26])
        passed[s] = true;
      vector<bool> npassed(N);
      queue<int> que;
      range(i, 0, passed.size()) if (passed[i]) que.push(i);
      while (!que.empty()) {
        int s = que.front();
        que.pop();
        for (int eid : f_cache[s])
          if ((es[eid].c == c || es[eid].c == '.') && !npassed[es[eid].t]) {
            npassed[es[eid].t] = true;
            que.push(es[eid].t);
          }
      }
      // eps trans
      range(i, 0, N) if (npassed[i]) for (int s : trans[i][26]) npassed[s] =
          true;
      range(s, 0, npassed.size()) if (npassed[s]) {
        bool alleps = true;
        for (int eid : f_cache[s])
          alleps &= es[eid].c == '-';
        // ???????????? ?? ????§???????????????´?????????????????? for ?????????
        if (alleps && t != s)
          continue;
        trans[st][c - 'A'].push_back(s);
      }
    }
  }
} NFA::ONE = NFA(1);

class REGtoNFA {
public:
  static NFA *pattern(string &s, int &i, int e) {
    NFA *p = simple(s, i, e);
    while (i < e && s[i] == '|') {
      i++; // '|'
      NFA *q = simple(s, i, e);
      p = NFA::Union(p, q);
    }
    return p;
  }
  static NFA *simple(string &s, int &i, int e) {
    NFA *p = basic(s, i, e);
    while (i < e && s[i] != '|') {
      NFA *q = basic(s, i, e);
      p = NFA::Concat(p, q);
    }
    return p;
  }
  static NFA *basic(string &s, int &i, int e) {
    NFA *p = elementary(s, i, e);
    if (i < (int)s.size() && s[i] == '*') {
      i++; // *
      p = NFA::Star(p);
    }
    return p;
  }
  static NFA *elementary(string &s, int &i, int e) {
    NFA *p;
    if (s[i] == '(') {
      i++; // (
      int d = 1;
      for (int j = i; j < e; j++) {
        if (s[j] == '(')
          d++;
        if (s[j] == ')')
          d--;
        if (d == 0) {
          e = j;
          break;
        }
      }
      p = pattern(s, i, e);
      i++; // )
    } else {
      p = new NFA(2);
      p->add_edge(s[i], p->s, p->t);
      i++; // c
    }
    return p;
  }
};

int rc = 0;
class Main {
public:
  int h, w;
  vector<string> tmp, res;

  vector<NFA> NFAs;
  vector<vector<int>> stats;

  void dfs(int y, int x, int c) {
    cerr << y << " " << x << endl;
    if (rc > 1)
      return;
    if (y == h) {
      rc += c;
      res = tmp;
      return;
    }
    // ????????????????????¶??????????????´????????????????????????????????¢?´¢
    vector<vector<vector<int>>> nstats(2, vector<vector<int>>(26));
    vector<int> nfai = {y, h + x};
    range(ni, 0, 2) for (char nc = 'A'; nc <= 'Z'; nc++) {
      for (int s : stats[nfai[ni]])
        for (int t : NFAs[nfai[ni]].trans[s][nc - 'A'])
          nstats[ni][nc - 'A'].push_back(t);
      UNIQUE(nstats[ni][nc - 'A']);
    }
    vector<int> gid(26);
    iota(ALL(gid), 0);
    for (char c1 = 'A'; c1 <= 'Z'; c1++)
      for (char c2 = 'A'; c2 < c1; c2++)
        if (gid[c2 - 'A'] == c2 - 'A') {
          if (nstats[0][c1 - 'A'].size() == nstats[0][c2 - 'A'].size() &&
              nstats[1][c1 - 'A'].size() == nstats[1][c2 - 'A'].size()) {
            bool eq = true;
            range(ni, 0, 2) {
              range(i, 0, nstats[ni][c1 - 'A'].size()) {
                eq &= nstats[ni][c1 - 'A'][i] == nstats[ni][c2 - 'A'][i];
                if (!eq)
                  break;
              }
              if (!eq)
                break;
            }
            if (eq) {
              gid[c1 - 'A'] = gid[c2 - 'A'];
              break;
            }
          }
        }
    vector<int> gc(26);
    range(i, 0, 26) gc[gid[i]]++;

    for (char c = 'A'; c <= 'Z'; c++)
      if (gid[c - 'A'] == c - 'A') {
        tmp[y][x] = c;
        bool tmpOK = true;
        // eda ??????????????? de ikerukana ?
        {
          bool ok = false;
          for (int s : nstats[0][c - 'A'])
            ok |= NFAs[y].reachable[s][w - 1 - x];
          tmpOK &= ok;
        }
        {
          bool ok = false;
          for (int s : nstats[1][c - 'A'])
            ok |= NFAs[h + x].reachable[s][h - 1 - y];
          tmpOK &= ok;
        }
        if (x == w - 1) {
          bool ok = false;
          for (int s : nstats[0][c - 'A'])
            ok |= s == NFAs[y].t;
          tmpOK &= ok;
        }
        if (y == h - 1) {
          bool ok = false;
          for (int s : nstats[1][c - 'A'])
            ok |= s == NFAs[h + x].t;
          tmpOK &= ok;
        }
        if (tmpOK) {
          vector<int> tmpp = stats[y], tmpq = stats[h + x];
          stats[y] = nstats[0][c - 'A'];
          stats[h + x] = nstats[1][c - 'A'];
          if (x + 1 < w)
            dfs(y, x + 1, gc[c - 'A']);
          else
            dfs(y + 1, 0, gc[c - 'A']);
          stats[y] = tmpp;
          stats[h + x] = tmpq;
        }
      }
  }

  void run() {
    while (true) {
      cin >> h >> w;
      if (h == 0 && w == 0)
        break;
      rc = 0;
      tmp = res = vector<string>(h, string(w, '-'));
      vector<string> ss(h + w);
      cin >> ss;
      // h <= 4, w <= 4
      NFAs = vector<NFA>(h + w);
      range(i, 0, h + w) {
        string s = "";
        range(j, 1, ss[i].size() - 1) s += ss[i][j];
        int cur = 0, e = s.size();
        NFAs[i] = *REGtoNFA::pattern(s, cur, e);
      }
      range(i, 0, h + w) {
        NFAs[i].create_reachable();
        NFAs[i].create_trans();
      }
      stats = vector<vector<int>>(h + w);
      range(i, 0, h + w) stats[i].push_back(NFAs[i].s);

      dfs(0, 0, 1);
      if (rc > 1) {
        cout << "ambiguous" << endl;
      } else if (rc == 0) {
        cout << "none" << endl;
      } else {
        range(i, 0, h) cout << res[i] << endl;
      }
    }
  }
};

int main() {
  cout << fixed << setprecision(20);
  cin.tie(0);
  ios::sync_with_stdio(false);
  Main().run();
  return 0;
}