Happy Number
EasyP2Coding
Start with a positive integer n and repeatedly replace it with the sum of the squares of its digits. The number is happy if this process reaches 1. Otherwise it loops forever in a cycle that never includes 1.
Return true if n is happy, otherwise false.
Example 1
- Input
- n = 19
- Output
- true
- Why
- 1^2 + 9^2 = 82, then 68, then 100, then 1.
Example 2
- Input
- n = 2
- Output
- false
- Why
- 2 -> 4 -> 16 -> 37 -> 58 -> 89 -> 145 -> 42 -> 20 -> 4, a cycle without 1.
Example 3
- Input
- n = 1
- Output
- true
Constraints
- 1 <= n <= 2^31 - 1
Hints
Give it a real attempt first. Run shows which examples fail.
Saved automatically
Run checks the 3 visible tests, Submit all 10. ⌘Enter runs, ⌘⇧Enter submits.