Find All Anagrams in a String

Given a string STR and a non-empty string PTR, your task is to identify all starting indices of PTR’s anagrams in STR.

Explanation:

An anagram of a string is another string that contains the same characters, just rearranged. For instance, 'SILENT' and 'LISTEN' are anagrams of each other, while 'ABA' and 'ABB' are not.

Input:

The first line of input includes an integer 'T', the number of test cases. Each test case consists of: - A line with two space-separated integers N and M, where N is the length of STR and M is the length of PTR. - A line containing the string STR. - A line containing the string PTR. 

Output:

For each test case, provide a sequence of all starting indices of the anagram substrings found in STR. Each test case's output should be on a new line.

Example:

Input: T = 1, N = 8, M = 3, STR = ACDBACDACB, PTR = ABC 
 Output: [3, 5, 6] 
 Explanation: 'BAC', 'CAB', and 'CAB' starting at positions 3, 5, and 6, respectively, are anagrams of 'ABC'. 

Constraints:

• 1 <= T <= 100
• 1 <= N <= 10⁵
• 1 <= M <= N
• STR and PTR consist only of uppercase English letters.
• Time limit: 1 second

Note:

Return the indices in ascending order. If no anagram is found, provide an empty sequence.