The title prolly ain't clear at all. You are given a string $$$s$$$ and a string $$$t$$$. For every substring $$$s$$$ of length $$$|t|$$$, you are to find the number of different characters between the substring of $$$s$$$ and $$$t$$$. It is guaranteed that $$$|t| \le |s|$$$.
Example: s: abac t: ag output: [1, 2, 1]
s: adfjaasd t: asdf output: [3, 4, 4, 4, 4]