Tontti

#include <iostream>

using namespace std;

#define fromto(var, from, to) for (plusgoodlong var = from; var < to; var++)
#define times(k) for (plusgoodlong __xxxx__ = 0; __xxxx__ < k; __xxxx__++)
#define INF 999999999

typedef long long plusgoodlong;

int main() {
	cin.sync_with_stdio(false);
	
	int n, m, x;
	cin >> n >> m >> x;
	
	int a = 0;
	
	int k[n+1][m+1][4];
	for (int i = 1; i <= n; i++) {
		string r;
		cin >> r;
		for (int j = 1; j <= m; j++) {
			k[i][j][0] = k[i][j][1] = r[j-1] == '*' ? (long)1 : (long)0;
			if (k[i][j][0] == x) a++;
		}
	}
	
	for (int s = 2; s <= min(n,m); s++) {
		int M = INF;
		for (int X = 1; X <= m; X++) {
			for (int Y = 1; Y <= n; Y++) {
				int nyk = 1+(s+2)%3;
				int ed = 1+(s+1)%3;
				int ed2 = 1+(s+0)%3;
				k[Y][X][nyk] = 0;
				if (X >= s && Y >= s) {
					k[Y][X][nyk] = k[Y][X][0];
					long t = s > 2 ? k[Y-1][X-1][ed2] : 0;
					long z = k[Y-s+1][X-s+1][0];
					long p = k[Y-1][X][ed];
					long q = k[Y][X-1][ed];
					
					//io.println("(" + X + ", " + Y + "; " + nyk + ", " + ed + ")[" + s + "] = " +
					//	k[Y][X][nyk] + " + " + p + " + " + q + " - " + t + " + " + z + " = " +
					//	(k[Y][X][nyk]+p+q-t+z));
					k[Y][X][nyk] += p + q - t + z;
				}
				M = min(M, k[Y][X][nyk]);
				if (k[Y][X][nyk] == x) {
					a++;
				}
			}
		}
		if (M > x) break;
	}
	
	cout << a << endl; }

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: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

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