Happy Number
Explore how to identify happy numbers by applying the fast and slow pointers pattern for cycle detection. Learn to implement an algorithm that checks whether a number reaches 1 or falls into a cycle, helping you solve this common coding interview problem efficiently.
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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.
export function isHappyNumber(n) {// Replace this placeholder return statement with your codereturn false;}