My IP has been banned from luogu for some reason, so I'm asking this question on CF.
Question:
If string S and T with same length has $$$k$$$ or less different characters, we say S matches T,
then if A and B are given, how to find every substring of A that matches B?
My English is poor, so there would be some grammar mistakes, but I think u can understand what I mean.
I don't need trivial solutions such as $$$O(n^2)$$$ (brute) or $$$O(nk\log n)$$$ (hash) or $$$O(\dfrac{n^2\Sigma}w)$$$ (bitset, probably not faster than brute).