Problem p00832 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <algorithm>
#include <cassert>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <functional>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>

using namespace std;

#define LOG(...) printf(__VA_ARGS__)
// #define LOG(...)
#define FOR(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define REP(i, n) for (int i = 0; i < (int)(n); ++i)
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define RSORT(c) sort((c).rbegin(), (c).rend())
#define CLR(a) memset((a), 0, sizeof(a))

typedef long long ll;
typedef unsigned long long ull;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

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

const int side[6][4] = {{2, 4, 5, 3}, {1, 3, 6, 4}, {1, 5, 6, 2},
                        {1, 2, 6, 5}, {1, 4, 6, 3}, {2, 3, 5, 4}};
const int dice_right[6][6] = {{0, 3, 5, 2, 4, 0}, {4, 0, 1, 6, 0, 3},
                              {2, 6, 0, 0, 1, 5}, {5, 1, 0, 0, 6, 2},
                              {3, 0, 6, 1, 0, 4}, {0, 4, 2, 5, 3, 0}};
struct UnionFind {
  vector<int> v;
  UnionFind(int n) : v(n) {
    for (int i = 0; i < n; i++)
      v[i] = i;
  }
  int find(int x) { return v[x] == x ? x : v[x] = find(v[x]); }
  void unite(int x, int y) { v[find(x)] = find(y); }
};
vi ans;
vector<vvi> dices(3, vvi(3, vi(3))); // men tate yoko
bool kakutei() {
  bool change = true;
  while (change) {
    change = false;
    REP(i, 3) {
      REP(j, 3) {
        if (dices[0][i][j] == 0) {
          REP(k, 3) {
            if (dices[1][k][j] > 0 && dices[2][k][2 - i] > 0) {
              dices[0][i][j] =
                  dice_right[dices[1][k][j] - 1][dices[2][k][2 - i] - 1];
              if (dices[0][i][j] == 0)
                return false;
              change = true;
            }
          }
        }
        if (dices[1][i][j] == 0) {
          REP(k, 3) {
            if (dices[0][k][j] > 0 && dices[2][i][2 - k] > 0) {
              dices[1][i][j] =
                  dice_right[dices[2][i][2 - k] - 1][dices[0][k][j] - 1];
              if (dices[1][i][j] == 0)
                return false;
              change = true;
            }
          }
        }
        if (dices[2][i][j] == -1) {
          REP(k, 3) {
            if (dices[0][2 - j][k] > 0 && dices[1][i][k] > 0) {
              dices[2][i][j] =
                  dice_right[dices[0][2 - j][k] - 1][dices[1][i][k] - 1];
              if (dices[2][i][j] == 0)
                return false;
              change = true;
            }
          }
        }
      }
    }
  }
  return true;
}
void dfs() {
  vector<vvi> copy_dices = dices;
  REP(i, 3) {
    REP(j, 3) {
      if (dices[0][i][j] == 0) {
        REP(k, 6) {
          bool clear = true;
          REP(l, 3) {
            if (dices[1][l][j] > 0)
              if (dices[1][l][j] == k + 1 || dices[1][l][j] + k + 1 == 7)
                clear = false;
            if (dices[2][l][2 - i] > 0)
              if (dices[2][l][2 - i] == k + 1 ||
                  dices[2][l][2 - i] + k + 1 == 7)
                clear = false;
          }
          if (clear) {
            dices[0][i][j] = k + 1;
            if (!kakutei()) {
              dices = copy_dices;
              continue;
            }
            int ex[3] = {0};
            REP(l, 3) {
              REP(x, 3) {
                REP(y, 3) {
                  if (dices[l][x][y] <= 0)
                    continue;
                  int a = dices[l][x][y];
                  if (a == 4)
                    a = 3;
                  if (a == 5)
                    a = 2;
                  if (a == 6)
                    a = 1;
                  ex[a - 1]++;
                  if (ex[a - 1] > 9)
                    clear = false;
                }
              }
            }
            if (!clear)
              continue;
            dfs();
            dices = copy_dices;
          }
        }
        return;
      }
      if (dices[1][i][j] == 0) {
        REP(k, 6) {
          bool clear = true;
          REP(l, 3)
          if (dices[0][l][j] == k + 1 || dices[0][l][j] + k + 1 == 7)
            clear = false;
          if (clear) {
            dices[1][i][j] = k + 1;
            if (!kakutei()) {
              dices = copy_dices;
              continue;
            }
            int ex[3] = {0};
            REP(l, 3) {
              REP(x, 3) {
                REP(y, 3) {
                  if (dices[l][x][y] <= 0)
                    continue;
                  int a = dices[l][x][y];
                  if (a == 4)
                    a = 3;
                  if (a == 5)
                    a = 2;
                  if (a == 6)
                    a = 1;
                  ex[a - 1]++;
                  if (ex[a - 1] > 9)
                    clear = false;
                }
              }
            }
            if (!clear)
              continue;
            dfs();
            dices = copy_dices;
          }
        }
        return;
      }
    }
  }
  int sum = 0;
  REP(i, 3) {
    REP(j, 3) { sum += dice_right[dices[0][2 - j][2] - 1][dices[1][i][2] - 1]; }
  }
  ans.push_back(sum);
}
int main() {
  int kurikaesu;
  cin >> kurikaesu;
  while (kurikaesu--) {
    ans.clear();
    REP(i, 3) {
      REP(j, 3) {
        REP(k, 3) { dices[i][j][k] = -1; }
      }
    }
    REP(i, 3) {
      REP(j, 3) { cin >> dices[0][i][j]; }
    }
    REP(i, 3) {
      REP(j, 3) { cin >> dices[1][i][j]; }
    }
    if (kakutei())
      dfs();
    else
      goto emp;
    SORT(ans);
    ans.erase(unique(ans.begin(), ans.end()), ans.end());
    REP(i, ans.size()) {
      cout << ans[i];
      if (i != ans.size() - 1)
        cout << ' ';
    }
  emp:
    if (ans.empty())
      cout << 0;
    cout << endl;
  }
}

Error: TLE

Fixed submission:

#include <algorithm>
#include <cassert>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <functional>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>

using namespace std;

#define LOG(...) printf(__VA_ARGS__)
// #define LOG(...)
#define FOR(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define REP(i, n) for (int i = 0; i < (int)(n); ++i)
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define RSORT(c) sort((c).rbegin(), (c).rend())
#define CLR(a) memset((a), 0, sizeof(a))

typedef long long ll;
typedef unsigned long long ull;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

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

const int side[6][4] = {{2, 4, 5, 3}, {1, 3, 6, 4}, {1, 5, 6, 2},
                        {1, 2, 6, 5}, {1, 4, 6, 3}, {2, 3, 5, 4}};
const int dice_right[6][6] = {{0, 3, 5, 2, 4, 0}, {4, 0, 1, 6, 0, 3},
                              {2, 6, 0, 0, 1, 5}, {5, 1, 0, 0, 6, 2},
                              {3, 0, 6, 1, 0, 4}, {0, 4, 2, 5, 3, 0}};
struct UnionFind {
  vector<int> v;
  UnionFind(int n) : v(n) {
    for (int i = 0; i < n; i++)
      v[i] = i;
  }
  int find(int x) { return v[x] == x ? x : v[x] = find(v[x]); }
  void unite(int x, int y) { v[find(x)] = find(y); }
};
vi ans;
vector<vvi> dices(3, vvi(3, vi(3))); // men tate yoko
bool kakutei() {
  bool change = true;
  while (change) {
    change = false;
    REP(i, 3) {
      REP(j, 3) {
        if (dices[0][i][j] == 0) {
          REP(k, 3) {
            if (dices[1][k][j] > 0 && dices[2][k][2 - i] > 0) {
              dices[0][i][j] =
                  dice_right[dices[1][k][j] - 1][dices[2][k][2 - i] - 1];
              if (dices[0][i][j] == 0)
                return false;
              change = true;
            }
          }
        }
        if (dices[1][i][j] == 0) {
          REP(k, 3) {
            if (dices[0][k][j] > 0 && dices[2][i][2 - k] > 0) {
              dices[1][i][j] =
                  dice_right[dices[2][i][2 - k] - 1][dices[0][k][j] - 1];
              if (dices[1][i][j] == 0)
                return false;
              change = true;
            }
          }
        }
        if (dices[2][i][j] == -1) {
          REP(k, 3) {
            if (dices[0][2 - j][k] > 0 && dices[1][i][k] > 0) {
              dices[2][i][j] =
                  dice_right[dices[0][2 - j][k] - 1][dices[1][i][k] - 1];
              if (dices[2][i][j] == 0)
                return false;
              change = true;
            }
          }
        }
      }
    }
  }
  return true;
}
void dfs() {
  vector<vvi> copy_dices = dices;
  REP(i, 3) {
    REP(j, 3) {
      if (dices[0][i][j] == 0) {
        REP(k, 6) {
          bool clear = true;
          REP(l, 3) {
            if (dices[1][l][j] > 0)
              if (dices[1][l][j] == k + 1 || dices[1][l][j] + k + 1 == 7)
                clear = false;
            if (dices[2][l][2 - i] > 0)
              if (dices[2][l][2 - i] == k + 1 ||
                  dices[2][l][2 - i] + k + 1 == 7)
                clear = false;
          }
          if (clear) {
            dices[0][i][j] = k + 1;
            if (!kakutei()) {
              dices = copy_dices;
              continue;
            }
            int ex[3] = {0};
            REP(l, 3) {
              REP(x, 3) {
                REP(y, 3) {
                  if (dices[l][x][y] <= 0)
                    continue;
                  int a = dices[l][x][y];
                  if (a == 4)
                    a = 3;
                  if (a == 5)
                    a = 2;
                  if (a == 6)
                    a = 1;
                  ex[a - 1]++;
                  if (ex[a - 1] > 9)
                    clear = false;
                }
              }
            }
            if (!clear)
              continue;
            dfs();
            dices = copy_dices;
          }
        }
        return;
      }
    }
  }
  REP(i, 3) {
    REP(j, 3) {
      if (dices[1][i][j] == 0) {
        REP(k, 6) {
          bool clear = true;
          REP(l, 3)
          if (dices[0][l][j] == k + 1 || dices[0][l][j] + k + 1 == 7)
            clear = false;
          if (clear) {
            dices[1][i][j] = k + 1;
            if (!kakutei()) {
              dices = copy_dices;
              continue;
            }
            int ex[3] = {0};
            REP(l, 3) {
              REP(x, 3) {
                REP(y, 3) {
                  if (dices[l][x][y] <= 0)
                    continue;
                  int a = dices[l][x][y];
                  if (a == 4)
                    a = 3;
                  if (a == 5)
                    a = 2;
                  if (a == 6)
                    a = 1;
                  ex[a - 1]++;
                  if (ex[a - 1] > 9)
                    clear = false;
                }
              }
            }
            if (!clear)
              continue;
            dfs();
            dices = copy_dices;
          }
        }
        return;
      }
    }
  }
  int sum = 0;
  REP(i, 3) {
    REP(j, 3) { sum += dice_right[dices[0][2 - j][2] - 1][dices[1][i][2] - 1]; }
  }
  ans.push_back(sum);
}
int main() {
  int kurikaesu;
  cin >> kurikaesu;
  while (kurikaesu--) {
    ans.clear();
    REP(i, 3) {
      REP(j, 3) {
        REP(k, 3) { dices[i][j][k] = -1; }
      }
    }
    REP(i, 3) {
      REP(j, 3) { cin >> dices[0][i][j]; }
    }
    REP(i, 3) {
      REP(j, 3) { cin >> dices[1][i][j]; }
    }
    if (kakutei())
      dfs();
    else
      goto emp;
    SORT(ans);
    ans.erase(unique(ans.begin(), ans.end()), ans.end());
    REP(i, ans.size()) {
      cout << ans[i];
      if (i != ans.size() - 1)
        cout << ' ';
    }
  emp:
    if (ans.empty())
      cout << 0;
    cout << endl;
  }
}