Untitled

#include <iostream>
#include <cmath>
#include <algorithm>
#include <cstdlib>
#include <string>
#include <cstdlib>
using namespace std;

int main() {
    int t;
    cin >> t;
    while (t--) {
        string x, d = "1111";
        int n;
        cin >> n;
        cin >> x;
        int c = sqrt(n);
        char m[c][c];
        if (c * c != n)
            cout << "No\n";
        else if (n == 4 && x == d)
            cout << "Yes\n";
        else {
            int z = 0;
            for (int i = 0; i < c; i++) {
                for (int k = 0; k < c; k++) {
                    m[i][k] = x[z++];
                }
            }
            bool f = true;
            for (int i = 0; i < c; ++i) {
                if (m[0][i] != '1' || m[i][0] != '1' || m[c - 1][i] != '1' || m[i][c - 1] != '1')
                    f = false;
            }
            for (int b = 1; b < (c - 1); b++) {
                for (int j = 1; j < (c - 1); j++) {
                    if (m[b][j] != '0')
                        f = false;
                }
            }
            if (f)
                cout << "Yes\n";
            else
                cout << "No\n";
        }
    }
        return 0;
}