LeetCode-Happy Number

標籤：

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.Example: 19 is a happy number12 + 92 = 8282 + 22 = 6862 + 82 = 10012 + 02 + 02 = 1

public class Solution {    public boolean isHappy(int n) {        Set<Integer> numberSet = new HashSet<Integer>();        while(n!=1){            if(!numberSet.add(n)){                return false;            }            char[] chars = String.valueOf(n).toCharArray();            int total = 0;            for(Character ch: chars){                total += Math.pow(Integer.parseInt(ch+""),2);            }            n = total;        }        return true;    }}

　　

LeetCode-Happy Number