#include <iostream>
    using namespace std;
    int arr[10] = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19};
    void swap(int p, int q)
    {
        int temp = arr[p];
        arr[p] = arr[q];
        arr[q] = temp;
        return;
    }
    void printArr(int size)
    {
        int k;
        for (k = 0; k < size; k++)
            cout << arr[k] << " ";
        cout << endl;
        return;
    }
    void Permutation(int n, int size)
    {
        int k;
        if (n == 0)
            printArr(size);
        else
        {
            for (k = n - 1; k >= 0; k--)
            {
                swap(k, n - 1);
                Permutation(n - 1, size);
                swap(k, n - 1);
            }
        }
        return;
    }
    int main()
    {
        Permutation(3, 4);
        return 0;
    }