This is just a silly project driven by "can I do it?" thought
Some time ago on JoeMonster I read about happy numbers https://en.wikipedia.org/wiki/Happy_number It's a perfect exercise after working with Spring, something light, no pressure.
1. method that checks if given number is Happy
1.1 tdd
1.2 working method ignoring Big-O
2. terminal interface
3. optimising method for better Big-O (non-adequate)
4. finding the closest Happy Number to number given by user
5. finding all happy Numbers in range given by user
6. method for finding happy Prime Numbers for all options
?. numbers n-happy (happy but when raised not to 2nd but n-th power)
I'm going to try TDD; I never really kept that principle, time was always short :( (so my skill) [it was not that hard and save me some time, when it was to decide what should be return type for the method]
Second thing to do is optimisation for better big-O notation result
##I consider it closed. All tests are green, aside for terminal UI, I managed to create methods for:
finding happy number
finding the closest happy number to given by user
finding all happy numbers in range given by user (minding that there would be two such numbers)
and corresponding methods for number which are both happy and prime
I may return to this project for making GUI, n-happy numbers are not so tempting; ist more of a writing than problem solving