Programming Examples
Java program to input a number and check whether it is a happy number or not
Write a program to input a number and check whether it is a happy number or not. If you iterate the process of summing the squares of the decimal digits of a number and if this process terminates in 1, then the original number is called a happy number. For example 7=> (72)=49=> (42+92)=97=>(92 +72)=130 =>(12 +32+02)=10 =>(12+02)= 1.
Solution
import java.util.*;
class HappyNumber
{
public static void main(int n)
{
Scanner sc=new Scanner(System.in);
int d,s,n;
System.out.println(“Enter a number:”);
n=sc.nextInt();
do
{
s=0;
while(n>0)
{
d=n%10;
s+=d*d;
n/=10;
}
n=s;
}while(n>9);
if(n==1)
System.out.println(“Happy Number”);
else
System.out.println(“Not a Happy Number”);
}
}
Output