Answer 1

hah, @VcC your challenge help me to solve this 😀

https://code.sololearn.com/W8Ot4n34o1xi/?ref=app

Answer 2

I think victory is mine. Sorry @ysraelcon

https://code.sololearn.com/cean4Mq567qa/?ref=app

Answer 3

It could be solved using recursion + memoization.. sorry but I can't code it now (laptop is not here 😁).. I'll code it as soon as possible

Answer 4

Discard mul div and drop, add concat in the following code : https://code.sololearn.com/ccQZXwI4XcH7/?ref=app