Submission #168966

#	Time	Username	Problem	Language	Result	Execution time	Memory
168966		abil	Bomb (IZhO17_bomb)	C++14	10 / 100	1089 ms	105712 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];
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++){
			if(a[i][j] == '1'){
				if(up[i][j] + down[i][j] - 1 < x || leftt[i][j] + rightt[i][j] - 1 < y){
					return false;
				}
			}
		}
	}
	return true;
}

bool check(int x){
	bool f = false;
	for(int i = 1;i * i <= x; i++){
		if(x % i == 0){
			if(solve(x / i, i) || solve(i, x / i)){
				f = true;
				break;
			}
		}
	}
	return f;
}
main()
{
	cin >> n >> m;
	for(int i = 1;i <= n; i++){
		for(int j = 1;j <= m; j++){
			cin >> a[i][j];
		}
	}
	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;
		}
	}
	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;
		}
	}
	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;
		}
	}
	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 l = 1, r = n * m; 
	while(r - l > 1){
		int mid = (r + l) >> 1;
		if(check(mid)){
			l = mid;
		}
		else{
			r = mid;
		}
	}
	if(check(r)){
		 l = r;
	}
	cout << l;
}

Compilation message (stderr)

bomb.cpp:45:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main()
      ^

• Subtask 1: 10 / 100