Question

1. An integer is said to be a perfect number if the sum of its divisors, including 1(but not the number itself), is equal to the number. For example, 6 is a perfect number because 6 = 1+2+3.

A) Write a function numPerfect( number ) that returns true when the number is a perfect number, false when it is not.

       B) Write a C# console program that calls the function in A) to determine and print all the perfect numbers between 1 and 2000. Print the divisors of each perfect number to confirm that the number is indeed perfect.

      C) Use the function in A) to determine and display how many perfect numbers there are between 5 and 5000.

Answer 1

CODE

using System;

class MainClass {

public static bool numPerfect(int number) {

int sum = 0;

//Console.Write("Divisors of " + number + " are : ");

for (int i = 1; i < number;i++) {

if (number % i == 0) {

sum = sum + i;

//Console.Write(i + " ");

}

}

//Console.WriteLine();

return sum == number;

}

public static void Main (string[] args) {

Console.Write("The Perfect numbers within the range 1 and 2000 : \n");

for (int i=1; i<=2000; i++) {

if (numPerfect(i)) {

Console.Write(i + " ");

}

}

int count = 0;

for (int i=5; i<=500; i++) {

if (numPerfect(i)) {

count ++;

}

}

Console.Write("\n\nCount of Perfect numbers within the range 5 and 5000 : " + count);

}

}