Grid

#include <iostream>
#include <cmath>
#include <string>
#include <vector>

using namespace std;

typedef long long LL;

int main(){
	LL n; cin >> n;
	vector<string> v;
	vector<bool> rowb(n);
	vector<bool> colb(n);
	int tot = 0;
	for (int i = 0; i < n; i++) {
		string s; cin >> s;
		v.emplace_back(s);
		for (char c : s) {
			if (c == '1') tot++;
		}
	}
	int rowtrue = 0;
	int coltrue = 0;
	for (int row = 0; row < n; row++) {
		int col = 0;
		for (; col < n; col++) {
			if (v[row][col] == '0') break;
		}
		if (col == n) { rowb[row] = true; rowtrue++; }
	}
	for (int col = 0; col < n; col++) {
		int row = 0;
		for (; row < n; row++) {
			if (v[row][col] == '0') break;
		}
		if (row == n) { colb[col] = true; coltrue++; }
	}
	if (rowtrue * n + coltrue * n - rowtrue*coltrue != tot) {
		cout << -1; return 0;
	}
	if (rowtrue == n || coltrue == n) {
		cout << n; return 0;
	}
	cout << rowtrue + coltrue;

}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED