1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
#include <bits/stdc++.h>
using namespace std;

void printMatrix(const vector<vector<int>> &matrix, const int n) {
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			printf("%2d ", matrix[i][j]);
		}
		printf("\n");
	}
}

int calculateMaxPath(vector<vector<int>> &m, const int n) {
	int result = 1;
	for (int k = 0; k < n; k++) {
//		cout << "k=" << k << endl;
//		printMatrix(m, n);
		for (int i = 0; i < n; i++) {
			if (i == k) { //
				continue;
			}
			for (int j = 0; j < n; j++) {
//				int col = m[i][k];
//				int row = m[k][j];
//				int val = m[i][j];
//				if (j == k || i == j || row == -1 || col == -1) {
				if (j == k || i == j || m[i][k] == -1 || m[k][j] == -1) {
					continue;
				}
//				int val2 = m[i][k] + m[k][j];
				m[i][j] =
						m[i][j] < 0 ?
								m[i][k] + m[k][j] :
								min(m[i][j], m[i][k] + m[k][j]);
				result = max(result, m[i][j]);
			}
		}
	}
	return result;
}
void findSolutin(const vector<vector<int>> &matrix, const int n) {
	vector<std::vector<int>> modified1 = matrix;
	int result = n;
	for (int i = 0; i < n; i++) {
		for (int j = i + 1; j < n; j++) {
			if (i == j) {
				continue;
			}
			vector<std::vector<int>> modified = matrix;
			modified[i][j] = 0;
			modified[j][i] = 0;
			result = min(result, calculateMaxPath(modified, n));

		}
	}
//	printMatrix(matrix, n);
//	printMatrix(modified, n);
	cout << result << endl;
}

int main() {
//	ifstream cin("tests/0a.in");
//	ifstream cin("tests1/tel1.in");

	cin.tie(NULL);
	cout.tie(NULL);
	ios_base::sync_with_stdio(false);

	int t;
	cin >> t;
	for (int test = 0; test < t; test++) {
		int n;
		cin >> n;
		vector<vector<int>> matrix(n, vector<int>(n));
		string s;

		for (int i = 0; i < n; i++) {
			cin >> s;
			for (int j = 0; j < n; j++) {
				matrix[i][j] = s[j] == '1' ? 1 : -1; // INT_MAX;
			}
			matrix[i][i] = 0;
		}
//		printMatrix(matrix, n);
		findSolutin(matrix, n);

	}

	return 0;
}