programming-examples/java/_Basics/Program to find perfect number or not. (Java).java
2019-11-15 12:59:38 +01:00

42 lines
1.3 KiB
Java

/*
A perfect number is a positive integer that is equal to the sum
of its proper positive divisors, that is, the sum of its positive
divisors excluding the number itself. Equivalently, a perfect number
is a number that is half the sum of all of its positive divisors.
The first perfect number is 6, because 1, 2 and 3 are its proper
positive divisors, and 1 + 2 + 3 = 6. Equivalently, the number 6
is equal to half the sum of all its positive divisors:
( 1 + 2 + 3 + 6 ) / 2 = 6.
*/
public class IsPerfectNumber
{
public boolean isPerfectNumber(int number)
{
int temp = 0;
for(int i=1; i<=number/2; i++)
{
if(number%i == 0)
{
temp += i;
}
}
if(temp == number)
{
System.out.println("It is a perfect number");
return true;
}
else
{
System.out.println("It is not a perfect number");
return false;
}
}
public static void main(String a[])
{
IsPerfectNumber ipn = new IsPerfectNumber();
System.out.println("Is perfect number: "+ipn.isPerfectNumber(28));
}
}