Happy Number

Problem

Return True if n is a happy number: repeatedly replace it with the sum of the squares of its digits, and check whether it eventually reaches 1.

Unhappy numbers fall into a cycle, so remember every value seen and stop if one repeats. Return False if the cycle is entered.

Hint

1 is happy by definition; every other happy chain eventually reaches it.

case 1

in: [19]

expected: true

case 2

in: [2]

expected: false

case 3

in: [1]

expected: true

case 4

in: [7]

expected: true

case 5

in: [4]

expected: false

Starter codePython

def happy_number(n):
    # Your code here
    pass

5 test cases · run your code against them in the editor