Question

Design a class Perfect to check if a given number is a perfect number or not. [ A number is said to be perfect if sum of the factors of the number excluding itself is equal to the original number]
Example : 6 = 1 + 2 + 3 (where 1, 2 and 3 are factors of 6, excluding itself)
Some of the members of the class are given below:
Class name Perfect
Data members/instance variables:
num:to store the number
Methods/Member functions:
Perfect (int nn):parameterized constructor to initialize the data member num=nn
int sum_of_factors(int i):returns the sum of the factors of the number(num), excluding itself, using recursive technique
void check():checks whether the given number is perfect by invoking the function sum_of_factors() and displays the result with an appropriate message
Specify the class Perfect giving details of the constructor (), int sum_of_factors(int) and void check (). Define a main () function to create an object and call the functions accordingly to enable the task.

Share code with your friends

Code

				
					import java.util.Scanner;
public class Perfect
{
    int num;
    Perfect(int nn)
    {
        num=nn;
    }

    int sum_of_factors(int i)
    {
        if (i == num) 
        {
            return 0;
        }
        else if(num%i==0)
        {
            return i + sum_of_factors((i+ 1));
        }
        else
        {
            return sum_of_factors((i+ 1));
        }
    }

    void check()
    {
        int s=sum_of_factors(1);
        if (s==num)
        {
            System.out.println(num+"is a perfect number");
        }
        else
        {
            System. out.println(num+"is not a perfect number");
        }
    }
    
    public static void main()
    {
        Scanner sc=new Scanner(System.in); 
        System.out.println("Enter a number");
        int num=sc.nextInt() ;
        Perfect ob1=new Perfect(num);
        ob1.check();	
    }
}