haha. How absolutely filthy of you! xD

!! 0 -> head

To be fair... with how finicky Haskell can get at times... it is part of why I've not attempted to do any Haskell translations as of yet.

This is from somebody who has attempted a few Bash translations... because of course I've attempted that.

This does not preserve list order as required by the kata description.

Seems your visited array is visible to all recursion branch?

hi @K01egA , g . f is not equivalent to f . g
if f: A->B and g: B->A
then

f . g = id_B
g . f = id_A

which imply that for all element b in B, we have id_B(b) = b
and for all element a in A ,we have id_A(a) = a

I was confuesed for a long time with (Integral i) => i -> String,feel free to comment this line, or you will use fromIntegral apply to n

Do not mix up isInfixOf and isSubsequenceOf :)

I used to take a subset of target string and count the number of subset strings which matches src，but always get timeout problem.(subset calculations are really cost)...
After coming to the toilet, the inspiration came and it was written in one breath.