Happy Number No 202

Java Solution

Posted by Captain Nimo 1 month ago

Question

Write an algorithm to determine if a number is "happy".

A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers.

code

 public boolean isHappy(int n ){  
  Set<Integer> s=new HashSet<Integer>();  
  while(n!=1){  
   int sum=0;  
   while(n!=0){  
    int mod=n%10;  
    sum+=mod*mod;  
    n/=10;  
   }  
   if(s.contains(sum)) return false;  
   s.add(n=sum);  
  }  
  return true;  
 }