Happy Number
Explore how to determine if a number is a happy number by applying the fast and slow pointer pattern. Understand the process of summing the squares of digits and detecting cycles to decide if a number leads to 1 or loops indefinitely.
We'll cover the following...
Statement
Write an algorithm to determine if a number is a happy number.
We use the following process to check if a given number is a happy number:
- Starting with the given number , replace the number with the sum of the squares of its digits.
- Repeat the process until:
- The number equals , which will depict that the given number is a happy number.
- The number enters a cycle, which will depict that the given number is not a happy number.
Return TRUE if is a happy number, and FALSE if not.
Constraints
Examples
Test your understanding of the problem
Let’s take a moment to make sure we have correctly understood the problem. The quiz below helps us to check that we are solving precisely the right problem:
Happy Number
(True or False) 28 is a happy number.
True
False
Figure it out
We have a game for you to play: re-arrange the logical building blocks to develop a clearer understanding of how to solve this problem.
Try it yourself
Implement your solution in the following coding playground.
import java.util.*;public class Main{public static boolean isHappyNumber(int n) {// Replace this placeholder return statement with your codereturn false;}}