Given a string S and a string T, count the number of distinct subsequences of T in S.

*should be reworded to*

Given a string S and a string T, count the number of distinct **subsequences of S which equals T**.

*or*

Given a string S and a string T, count the number of distinct **sequences of T** in S.

In the original description, *subsequences of T* could be any subsequences which are not necessary to be equal to T.

@administrators Can you please improve the description?