#include <iostream>

using namespace std;

bool check_if_number_exists(int a[], int n, int nr)
{
    if (n == - 1)
        return false;

    if (a[n - 1] == nr)
        return true;

    return check_if_number_exists(a, n - 1, nr);
}

bool check_duplicates(int a[], int n)
{
    if (n == 1)
        return false;

    if (check_if_number_exists(a, n -1, a[n - 1]))
        return true;

    return check_duplicates(a, n - 1);
}

int main()
{
    int a[] = {1, 2, 6, 3, 5};

    cout << check_duplicates(a, 5);
    return 0;
}