Print '1' in Main and Secondary Diagonals in Matrix using C++

#include <bits/stdc++.h>

using namespace std;

int main() {
    int n;
    cin >> n;
    vector<vector<int>> a(n, vector<int>(n, 0));
    for (int i = 0; i < n; i++) {
        a[i][i] = 1;
        a[i][n - 1 - i] = 1;
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            cout << a[i][j] << " ";
        }
        cout << '\n';
    }
    return 0;
}