Even Grid

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define pb push_back
#define VI vector<int>
#define AR(x) array<int, x>
#define MX vector<VI >
#define all(x) x.begin(), x.end()
#define IOS cin.tie(0)->sync_with_stdio(0)

using namespace std;

int main(){

    int n;
    cin >> n;

    vector<string> s(n);
    for(string &i : s) cin >> i;

    for(int i=1; i<n; i++){
        if(s[i][0] == '1'){
            for(int j=1; j<n; j++) s[i][j] = s[0][j];
        } else {
            for(int j=1; j<n; j++) s[i][j] = '0';
        }
    }

    for(string i : s) cout << i << '\n';

    return 0;
}

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