Exercise 4

#include <iostream>
#include <string>

int proper_positive_divisors_sum(int number)
{
    int remainder = 0;
    int sum = 0;

    for (int index = 1; index < number; index++)
    {
        remainder = (number % index);

        if (remainder == 0)
        {
            sum = sum + index;
        }
    }

    return sum;
}

bool numbers_are_betrothed(int number1, int number2)
{
    int sum_of_number1 = proper_positive_divisors_sum(number1);
    int sum_of_number2 = proper_positive_divisors_sum(number2);

    if (number1 == sum_of_number2-1 && number2 == sum_of_number1-1)
    {
        return true;
    }
    else
    {
        return false;
    }
}

void print_betrothed_numbers(int n)
{
    for (int index1 = 0; index1 < n; index1++)
    {
        for (int index2 = 0; index2 <= index1; index2++)
        {
            if (index1 < n || index2 < n)
            {
                if (numbers_are_betrothed(index1, index2))
                {
                    printf("(%d, %d)\n", index2, index1);
                }
            }
        }
    }
}

int main()
{
    print_betrothed_numbers(100);

    return 0;
}