using System;
namespace lab
{
class Programm
{
static int CalcSumOfDivisors(int number)
{
int sumOfDivisors = 0;
for(int divisor = 1; divisor != number / 2 + 1; divisor++)
{
if (number % divisor == 0)
sumOfDivisors += divisor;
}
return sumOfDivisors;
}
static void PrintAllPerfectNumbers(int maxNumber)
{
Console.WriteLine("Досконалі числа: ");
for (int number = 2; number <= maxNumber; number++)
{
if (CalcSumOfDivisors(number) == number)
Console.WriteLine(number);
}
}
static void PrintAllAmicableNumbersPairs(int maxNumber)
{
Console.WriteLine("Пари дружніх чисел: ");
for (int firstNumber = 2; firstNumber <= maxNumber; firstNumber++)
{
int secondNumber = CalcSumOfDivisors(firstNumber);
if (firstNumber < secondNumber && firstNumber == CalcSumOfDivisors(secondNumber) && secondNumber <= maxNumber)
Console.WriteLine($"{firstNumber} {secondNumber}");
}
}
static void Main(string[] args)
{
Console.Write("Введіть до якого числа виконувати операції: ");
int number = Convert.ToInt32(Console.ReadLine());
PrintAllPerfectNumbers(number);
PrintAllAmicableNumbersPairs(number);
}
}
}