Distinct Occurrences Problem Statement

You are given two strings 'A' and 'B' of lengths 'N' and 'M' respectively. Your task is to determine how many distinct ways string 'B' occurs as a subsequence in string 'A'.

Input:

An integer 'T' representing the number of test cases.
Each test case contains:
- An integer 'N', representing the length of string 'A'.
- An integer 'M', representing the length of string 'B'.
- A string 'A'.
- A string 'B'.

Output:

For each test case, output a single integer indicating the number of distinct occurrences of 'B' in 'A' as a subsequence.

Example:

Input:

T = 1
N = 6, M = 2
'A' = 'aabbcc'
'B' = 'abc'

Output:

3

Explanation:

The subsequences of 'A' matching 'B' are 'abc' (from 1st 'a', 1st 'b', and 1st 'c'), 'abc' (from 1st 'a', 2nd 'b', and 2nd 'c'), and 'abc' (from 2nd 'a', 2nd 'b', and 2nd 'c'). Therefore, there are 3 distinct subsequences.

Constraints:

• 1 <= T <= 100
• 1 <= N, M <= 100
• Time limit: 1 second

Note:

A subsequence is a sequence derived from another sequence by deleting some elements without changing the order of the remaining elements.