Happy Number
A "Happy Number" is defined as a number that after finite number of "steps" - where
we sum the square of each digit each time - the result is a 1. Given a number n,
determine whether it is a happy number.
As a challenge, complete this question under constant space.
Parameters
n: The number to check.
Result
trueorfalse, depending on whether this number is a happy number.
Examples
Example 1
Input: n = 19
Output: true
Explanation:
1^2 + 9^2 = 82
8^2 + 2^2 = 68
6^2 + 8^2 = 100
1^2 + 0^2 + 0^2 = 1Example 2
Input: n = 2
Output: false
Explanation:
2^2 = 4
4^2 = 16
1^2 + 6^2 = 37
3^2 + 7^2 = 58
5^2 + 8^2 = 89
8^2 + 9^2 = 145
1^2 + 4^2 + 5^2 = 42
4^2 + 2^2 = 18
1^2 + 8^2 = 65
6^2 + 5^2 = 61
6^2 + 1^2 = 37
...
Constraints
1 <= n < 2^31
Try it yourself
Solution
Title
Script
Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.
Contrary to popular belief, Lorem Ipsum is not simply random text.
>>> a = [1, 2, 3]
>>> a[-1]
3