Tontti

#include <iostream>
#include <math.h>

using namespace std;

#define ull unsigned long long

int main() {
	cin.sync_with_stdio(false);
	int i, j, n, m, k, x, s, sz, q, w, b;
	cin >> n >> m >> k;
	char input[n][m];
	int a[n*m];
	int f[n*m];
	for (i = 0; i < n; i++)
		cin >> input[i];
	sz = (int)ceil(sqrt((double)k));
	x = b = 0;
	for (i = 0; i < n; i++)
		for (j = 0; j < m; j++) {
			a[i*n+j] = !(input[i][j]=='.');
			f[i*n+j] = 0;
			if(k<2)
				x += a[i*n+j]^k^1;
		}
	int c = max(sz,2);
	for (s = c; s <= min(n,m); s++) {
		for (i = s - 1; i < n; i++)
			for (j = s - 1; j < m; j++) {
				int t = f[i*n+j];
				if (s == c) {
					for (q = i - s + 1; q <= i; q++) {
						for (w = j - s + 1; w <= j; w++) {
							t += a[q*n+w];
						}
					}
					f[i*n+j] = t;
				} else {
					for (q = 0; q < s - 1; q++) {
						t += a[(i-s+1)*n+j-q];
						t += a[(i-q)*n+j-s+1];
					}
					t += a[(i-s+1)*n+j-s+1];
					f[i*n+j] = t;
				}
				b = 0;
				if (t == k) x++;
			}
	}
	cout << x << "\n";
	return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 7

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 8

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 9

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 10

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 11

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 14

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED