Problem p00116 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
using namespace std;
typedef long long ll;
const double EPS = 1e-9;
typedef vector<int> vint;
typedef pair<int, int> pint;
#define rep(i, n) REP(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define MSG(a) cout << #a << " " << a << endl;
#define REP(i, x, n) for (int i = x; i < n; i++)
template <class T, class C> void chmax(T &a, C b) {
  if (a < b)
    a = b;
}
template <class T, class C> void chmin(T &a, C b) {
  if (b < a)
    a = b;
}
template <class T, class C> pair<T, C> mp(T a, C b) { return make_pair(a, b); }

int main() {
  int H, W;
  while (cin >> H >> W && H) {
    vector<string> field(H);
    vector<vint> dp(H, vint(W, 0));

    rep(i, H) cin >> field[i];

    rep(y, H) rep(x, W) for (int dx = 0; x + dx < W && field[y][x + dx] == '.';
                             dx++) dp[y][x]++;

    int res = 0;
    rep(y, H) rep(x, W) {
      int mi = 1 << 30;
      rep(k, y + 1) {
        chmin(mi, dp[y - k][x]);
        chmax(res, mi * (k + 1));
      }
    }

    cout << res << endl;
  }
}

Error: TLE

Fixed submission:


#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
using namespace std;
typedef long long ll;
const double EPS = 1e-9;
typedef vector<int> vint;
typedef pair<int, int> pint;
#define rep(i, n) REP(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define MSG(a) cout << #a << " " << a << endl;
#define REP(i, x, n) for (int i = x; i < n; i++)
template <class T, class C> void chmax(T &a, C b) {
  if (a < b)
    a = b;
}
template <class T, class C> void chmin(T &a, C b) {
  if (b < a)
    a = b;
}
template <class T, class C> pair<T, C> mp(T a, C b) { return make_pair(a, b); }

int main() {
  int H, W;
  while (cin >> H >> W && H) {
    vector<string> field(H);
    vector<vint> dp(H + 1, vint(W + 1));

    rep(i, H) cin >> field[i];

    rep(i, W + 1) dp[0][i] = i + 1;
    rep(i, H + 1) dp[i][0] = i + 1;

    REP(y, 1, H + 1) REP(x, 1, W + 1) {
      dp[y][x] = dp[y - 1][x] + dp[y][x - 1] - dp[y - 1][x - 1] +
                 (field[y - 1][x - 1] == '*');
    }

    // rep(y, H + 1) rep(x, W + 1)
    // cout << dp[y][x] << (x == W ? "\\n" : " ");

    int size = 0, y, x, sx, sy;
    for (y = 1; y <= H; y++) {
      for (x = 1; x <= W; x++) {
        for (sx = x; sx; sx--) {
          for (sy = y; sy; sy--) {
            if (sx * sy < size)
              break;
            if (dp[y][x] - dp[y - sy][x] - dp[y][x - sx] + dp[y - sy][x - sx] ==
                0) {
              chmax(size, sx * sy);
              break;
            }
          }
        }
      }
    }

    cout << size << endl;
  }
}