#include <iostream>
#include <string>

#define SIZE 4

void printVariationsWithRepetitions(char * arr, std::string variation, int size, int length)
{
	if (length == 0)
	{
		std::cout << variation << '\n';
		return;
	}


	for (int i = 0; i < size; ++i)
	{
		std::string newVariation;
		newVariation = variation + arr[i];
		printVariationsWithRepetitions(arr, newVariation, size, length - 1);
	}
}


int main()
{
	char arrayOfLetters[SIZE] = { 'A','B','C','D' };
	int length = 3;
	printVariationsWithRepetitions(arrayOfLetters, "", SIZE, length);



	return 0;
}