Question

Write a C++ program to print all the perfect numbers below a certain given number.

A perfect number is a number that that is equal too the sum of it's divisors other than itself . For example, 6 and 28 are all perfect numbers.

6 = ( 1+2 +3)

28 = (1+2+4+7+14)

Make sure your program conforms to the following requirements:

1. Accept the upper limit from the user (as an integer).

2. Make sure the number is positive (at least 1).

3. Go from 1 to to the upper limit and print all numbers that are perfect.

Sample Runs:

NOTE: not all possible runs are shown below.

Sample Run 1

Welcome to the locate perfect numbers program...
What is the upper value?30
The following are perfect numbers...
6
28

Process finished with exit code 0

Sample Run 2

Welcome to the locate perfect numbers program...
What is the upper value?-8
What is the upper value? (must be an integer > 0)0
What is the upper value? (must be an integer > 0)500
The following are perfect numbers...
6
28
496

Answer 1

In case of any query, do comment. Please rate your answer. Thanks

Please use below code:

#include <iostream>

using namespace std;

int main()

{

    int upperValue = 0, sumOfDivisors=0;

    cout<<"Welcome to the locate perfect numbers program..."<<endl;

    cout<<"What is the upper value? " ;

   

    cin>> upperValue;

    //if upper value not in range, ask again to take input

    while(upperValue <= 0)

    {

        cout<<"What is the upper value? (must be an integer > 0) ";

        cin>> upperValue;

    }

  

    //Print the perfect numbers

    cout<<"The following are perfect numbers..."<<endl;

    //iterate through 1 to uppervalue

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

        //reset the sum of divisors to 0

        sumOfDivisors =0;

      

        for(int i=1; i<number; i++)

        {

            //find divisor of the number and add it to sumOfDivisors

            if(number % i == 0)

            {

                sumOfDivisors = sumOfDivisors + i;

            }

        }

       

        //after all divisors check if sumOfDivisors is equal to number then print the number

        if(sumOfDivisors == number)

            cout<< number<< endl;

    }

        

   

    return 0;

}

===================screen shot of the code=========================

Output: