Problem p01349 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <algorithm>
#include <bitset>
#include <cctype>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

using namespace std;

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();
}
template <class T> inline T sqr(T x) { return x * x; }

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;

#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define pb push_back
#define mp make_pair
#define each(i, c)                                                             \\
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define exist(s, e) ((s).find(e) != (s).end())
#define range(i, a, b) for (int i = (a); i < (b); ++i)
#define rep(i, n) range(i, 0, n)
#define clr(a, b) memset((a), (b), sizeof(a))
#define dump(x) cerr << #x << " = " << (x) << endl;
#define debug(x)                                                               \\
  cerr << #x << " = " << (x) << " (L" << __LINE__ << ")"                       \\
       << " " << __FILE__ << endl;

const double eps = 1e-10;
const double pi = acos(-1.0);
const ll INF = 1LL << 62;
const int inf = 1 << 29;

int main(void) {
  string res;
  for (int h, w, n; cin >> h >> w >> n; cout << res << endl) {
    res = "NO";
    vs orim(h);
    rep(y, h) { cin >> orim[y]; }

    rep(y, h) {
      range(x, 1, w) {
        vs m = orim;
        if (m[y][x] == '.' && m[y][x - 1] == '.')
          continue;

        swap(m[y][x], m[y][x - 1]);

        bool ok;
        do {
          for (int y = h - 1; 0 <= y; y--) {
            rep(x, w) {
              if (m[y][x] == '.') {
                int yy = y;
                while (0 <= --yy) {
                  if (m[yy][x] != '.') {
                    m[y][x] = m[yy][x];
                    m[yy][x] = '.';
                    break;
                  }
                }
              }
            }
          }

          ok = false;
          vvi del(h, vi(w));

          rep(y, h) {
            rep(x, w) {
              if (m[y][x] == '.')
                continue;

              char c = m[y][x];
              int cnt = 1;
              for (int sign = -1; sign < 2; sign += 2) {
                int xx = x;

                while (0 <= (xx += sign) && xx < w && m[y][xx] == c)
                  cnt++;
              }
              if (n <= cnt) {
                for (int sign = -1; sign < 2; sign += 2) {
                  int xx = x;

                  while (0 <= (xx += sign) && xx < w && m[y][xx] == c)
                    del[y][xx] = true;
                }
              }

              cnt = 1;
              for (int sign = -1; sign < 2; sign += 2) {
                int yy = y;

                while (0 <= (yy += sign) && yy < h && m[yy][x] == c)
                  cnt++;
              }
              if (n <= cnt) {
                for (int sign = -1; sign < 2; sign += 2) {
                  int yy = y;

                  while (0 <= (yy += sign) && yy < h && m[yy][x] == c)
                    del[yy][x] = true;
                }
              }
            }
          }

          rep(y, h) {
            rep(x, w) {
              if (del[y][x]) {
                ok = true;
                m[y][x] = '.';
              }
            }
          }
        } while (ok);

        ok = true;
        rep(y, h) {
          rep(x, w) {
            if (m[y][x] != '.')
              ok = false;
          }
        }

        if (ok) {
          res = "YES";
        }
      }
    }
  }

  return 0;
}

Error: TLE

Fixed submission:

#include <algorithm>
#include <bitset>
#include <cctype>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

using namespace std;

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();
}
template <class T> inline T sqr(T x) { return x * x; }

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;

#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define pb push_back
#define mp make_pair
#define each(i, c)                                                             \\
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define exist(s, e) ((s).find(e) != (s).end())
#define range(i, a, b) for (int i = (a); i < (b); ++i)
#define rep(i, n) range(i, 0, n)
#define clr(a, b) memset((a), (b), sizeof(a))
#define dump(x) cerr << #x << " = " << (x) << endl;
#define debug(x)                                                               \\
  cerr << #x << " = " << (x) << " (L" << __LINE__ << ")"                       \\
       << " " << __FILE__ << endl;

const double eps = 1e-10;
const double pi = acos(-1.0);
const ll INF = 1LL << 62;
const int inf = 1 << 29;

int main(void) {
  string res;
  for (int h, w, n; cin >> h >> w >> n, h; cout << res << endl) {
    res = "NO";
    vs orim(h);
    rep(y, h) { cin >> orim[y]; }

    rep(y, h) {
      range(x, 1, w) {
        vs m = orim;
        if (m[y][x] == '.' && m[y][x - 1] == '.')
          continue;

        swap(m[y][x], m[y][x - 1]);

        bool ok;
        do {
          ok = false;
          vvi del(h, vi(w));

          rep(y, h) {
            rep(x, w) {
              if (m[y][x] == '.')
                continue;

              char c = m[y][x];
              int cnt = 1;
              for (int sign = -1; sign < 2; sign += 2) {
                int xx = x;

                while (0 <= (xx += sign) && xx < w && m[y][xx] == c)
                  cnt++;
              }
              if (3 <= cnt) {
                for (int sign = -1; sign < 2; sign += 2) {
                  int xx = x;

                  while (0 <= (xx += sign) && xx < w && m[y][xx] == c)
                    del[y][xx] = true;
                }
              }

              cnt = 1;
              for (int sign = -1; sign < 2; sign += 2) {
                int yy = y;

                while (0 <= (yy += sign) && yy < h && m[yy][x] == c)
                  cnt++;
              }
              if (3 <= cnt) {
                for (int sign = -1; sign < 2; sign += 2) {
                  int yy = y;

                  while (0 <= (yy += sign) && yy < h && m[yy][x] == c)
                    del[yy][x] = true;
                }
              }
            }
          }

          rep(y, h) {
            rep(x, w) {
              if (del[y][x]) {
                ok = true;
                m[y][x] = '.';
              }
            }
          }

          for (int y = h - 1; 0 <= y; y--) {
            rep(x, w) {
              if (m[y][x] == '.') {
                int yy = y;
                while (0 <= --yy) {
                  if (m[yy][x] != '.') {
                    m[y][x] = m[yy][x];
                    m[yy][x] = '.';
                    break;
                  }
                }
              }
            }
          }
        } while (ok);

        ok = true;
        rep(y, h) {
          rep(x, w) {
            if (m[y][x] != '.')
              ok = false;
          }
        }

        if (ok) {
          res = "YES";
        }
      }
    }
  }

  return 0;
}