Submission #168981

#	Time	Username	Problem	Language	Result	Execution time	Memory
168981		abil	Bomb (IZhO17_bomb)	C++14	22 / 100	1099 ms	111352 KiB

bomb

#include <bits/stdc++.h>

#define fr first
#define sc second
#define pb push_back
#define mk make_pair
#define all(s) s.begin(),s.end()
//#define int long long

using namespace std;

const int N = (2500 + 12);
const int mod = (1e9 + 7);
const int INF = (0x3f3f3f3f);

char a[N][N], b[N][N];
int up[N][N], down[N][N], leftt[N][N], rightt[N][N];

int n, m;
bool solve(int x,int y){
	for(int i = 1;i <= n; i++){
		for(int j = 1;j <= m; j++){
			b[i][j] = '0';
		}
	}
	for(int i = 1;i <= n; i++){
		for(int j = 1;j <= m; j++){
			if(a[i][j] == '1' && i >= x && j >= y){
				int cnt = 0;
				for(int k = i - x + 1; k <= i; k++){
					for(int l = j - y + 1; l <= j; l++){
						cnt += (a[k][l] == '1');
					}
				}
				if(cnt == x * y){
					for(int k = i - x + 1; k <= i; k++){
						for(int l = j - y + 1; l <= j; l++){
							b[k][l] = '1';
						}
					}
				}
			}
		}
	}
	for(int i = 1;i <= n; i++){
		for(int j = 1;j <= m; j++){
			if(a[i][j] != b[i][j]){
				return false;
			}
		}
	}
	return true;
}

main()
{
	cin >> n >> m;
	for(int i = 1;i <= n; i++){
		for(int j = 1;j <= m; j++){
			cin >> a[i][j];
		}
	}
	int mnx = INF, mny = INF;
	for(int i = 1;i <= n; i++){
		int cnt = 0;
		for(int j = 1;j <= m; j++){
			cnt = (a[i][j] == '0' ? 0 : cnt + 1);
			leftt[i][j] = cnt;
			mny = min(mny, leftt[i][j]);
		}
	}
	for(int i = 1;i <= n; i++){
		int cnt = 0;
		for(int j = m;j >= 1; j--){
			cnt = (a[i][j] == '0' ? 0 : cnt + 1);
			rightt[i][j] = cnt;
			mny = min(mny, rightt[i][j]);
		}
	}
	for(int i = 1;i <= m; i++){
		int cnt = 0;
		for(int j = 1;j <= n; j++){
			cnt = (a[j][i] == '0' ? 0 : cnt + 1);
			up[j][i] = cnt;
			mnx = min(mnx, up[j][i]);
		}
	}
	for(int i = 1;i <= m; i++){
		int cnt = 0;
		for(int j = n;j >= 1; j--){
			cnt = (a[j][i] == '0' ? 0 : cnt + 1);
			down[j][i] = cnt;
		}
	}
	int ans = 0;
	for(int i = 1;i <= n; i++){
		for(int j = 1;j <= m; j++){
			if(solve(i,j)){
				ans = max(ans, i * j);
			}
		}
	}
	cout << ans;
}
/*
20 20
11111000000000000000
11111000000000000000
11111100000000000000
11111111111000000000
00000111111000000000
00000111111000000000
00000011111000000000
00000001111100000000
00000000111110000000
00000000111110000000
00000000111110000000
00000000111110000000
00000000000000000000
00000000000000000000
00000000000000000000
00000000000000000000
00000000000000000000
00000000000000000000
00000000000000000000
00000000000000000000
*/

Compilation message (stderr)

bomb.cpp:55:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main()
      ^

• Subtask 1: 22 / 100