@enji ^^^
What? I'm not sure what you mean. I am talking about saying "Get sum of nth row for Pascals Triangle" kind of thing. I know it isn't Pascals Triangle. I don't know what this is called.

@bobthelantern I totally didn't see it lol.

My only suggestion is a hint to the solution, a link to a mathisfun page or something. I'm not asking for the solution, just a lead. I was looking up this problem for an algorithm I could learn, but I couldn't find anything at all. I don't know how people came up with that solution...

It just sucks to come up with a plan and finally find your solution, only see that 600+ people solved it in 1 line.

Have thoughts...

1. I spent most of time figuring out what the tests were doing and what exactly my inputs were rather than solving the problem. Essentially, what the test taker needed to do, was a 7 kyu, readying the tests/inputes was not.
2. I have no idea what "Hajime" is, but a DDG search seems to mean "Start"? But that is the end, when you already have your list.

How did you avoid the warning about comparing an int to size_t?

My code kept failing the attempt till I put in the print statement and then it just passed all of a sudden... I think the malloc was failing? I don't know.

I am very impressed with this. I had no idea replace would just return the string if it fails to find the item.