Happy number in java
Any positive natural integer number square of its digit
and sum it up and repeat the sequence until reach in single digit. If the single digit is 1 and then it is a happy number otherwise not a happy number.
Example
28
2x2 + 8x8 = 4 + 64 = 68
6x6 + 8x8 = 36 + 64 = 100
1x1 + 0x0 + 0x0 = 1 + 0 + 0 = 1
In the following program a number is input from the
main() method and that number is pass to the isHappyNumber(int number) method
where it will sum the square of its
digit and then again do the same until the sum come’s in single digit. That
digit return to the main() method and check the number, if it is 1 the it is
called Happy Number else not a Happy number.
import
java.util.Scanner;
public
class HappyNumberinJava
{
int reminder, sum, num ; // Instance Variable
// Constructor
public HappyNumberinJava()
{
sum = 0;
num = 0;
}
public int isHappyNumber(int number)
{
num = number;
while (num > 9)
{
while (num > 0)
{
reminder = num % 10;
sum = sum + (reminder *
reminder);
num = num / 10;
}
num = sum;
sum = 0;
}
return num;
}
// main() method
public static void main(String[] args)
{
int n; // Take the number
int rnumber; // value from the function
HappyNumberinJava ob = new
HappyNumberinJava(); // object
Scanner sc = new Scanner(System.in);
System.out.println("Enter a number
to check happy number :");
n = sc.nextInt();
rnumber = ob.isHappyNumber(n);
if(rnumber == 1)
{
System.out.println("Happy
number");
}
else
{
System.out.println("Not a
happy number");
}
}
}
Java program
