swap diags

#include <iostream>
using namespace std;

int main()
{
    int n, a[100][100];
    cin >> n;
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            cin >> a[i][j];
    for (int i = 0; i < n; i++)
            {
                int aux = a[i][j];
                a[i][j] = a[i][n - i - 1];
                a[i][n - i - 1] = aux;
            }
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
            cout << a[i][j] << ' ';
        cout << endl;
    }
    return 0;
}