Submission #973332

#	Time	Username	Problem	Language	Result	Execution time	Memory
973332		MilosMilutinovic	Bomb (IZhO17_bomb)	C++14	24 / 100	102 ms	80960 KiB

bomb

#include <bits/stdc++.h>
 
using namespace std;
 
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  vector<string> s(n);
  for (int i = 0; i < n; i++) {
    cin >> s[i];
  }
  vector<vector<int>> U(n, vector<int>(m));
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (s[i][j] == '0') {
        continue; 
      }
      U[i][j] = (i == 0 || s[i - 1][j] == '0' ? i : U[i - 1][j]);
    }
  }
  vector<vector<int>> D(n, vector<int>(m));
  for (int i = n - 1; i >= 0; i--) {
    for (int j = 0; j < m; j++) {
      if (s[i][j] == '0') {
        continue;
      }
      D[i][j] = (i == n - 1 || s[i + 1][j] == '0' ? i : D[i + 1][j]);
    }
  }
  vector<vector<int>> len(n, vector<int>(m));
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (s[i][j] == '0') {
        continue;
      }
      len[i][j] = D[i][j] - U[i][j] + 1;
    }
  }
  int width = m;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (s[i][j] == '0') {
        continue;
      }
      int ptr = j;
      while (ptr + 1 < m && s[i][ptr + 1] == '1') {
        ptr += 1;
      }
      width = min(width, ptr - j + 1);
      j = ptr;
    }
  }
  int height = n;
  for (int j = 0; j < m; j++) {
    for (int i = 0; i < n; i++) {
      if (s[i][j] == '0') {
        continue;
      }
      int ptr = i;
      while (ptr + 1 < n && s[ptr + 1][j] == '1') {
        ptr += 1;
      }
      height = min(height, ptr - i + 1);
      i = ptr;
    }
  }
  vector<int> mx(m + 1, height);
  for (int i = 0; i < n; i++) {
    int bef = -1;
    int val = (int) 1e9;
    for (int j = 0; j < m; j++) {
      if (s[i][j] == '0') {
        bef = j;
        val = (int) 1e9;
        continue;
      }
      val = min(val, len[i][j]);
      mx[j - bef] = min(mx[j - bef], val);
    }
  }
  for (int i = 0; i < n; i++) {
    int bef = m;
    int val = (int) 1e9;
    for (int j = m - 1; j >= 0; j--) {
      if (s[i][j] == '0') {
        bef = j;
        val = (int) 1e9;
        continue;
      }
      val = min(val, len[i][j]);
      mx[bef - j] = min(mx[bef - j], val);
    }
  }
  for (int i = 1; i < width; i++) {
    mx[i + 1] = min(mx[i + 1], mx[i]);
  }
  int res = 0;
  for (int i = 1; i <= width; i++) {
    res = max(res, mx[i] * i);
  }
  cout << res << '\n';
  return 0;
}

• Subtask 1: 24 / 100