09 String Anagrams (hard)

Given a string and a pattern, find all anagrams of the pattern in the given string.

Every anagram is a permutation of a string. As we know, when we are not allowed to repeat characters while finding permutations of a string, we get N!N! permutations (or anagrams) of a string having NN characters. For example, here are the six anagrams of the string “abc”:

1. abc
2. acb
3. bac
4. bca
5. cab
6. cba

Write a function to return a list of starting indices of the anagrams of the pattern in the given string.

Example 1:

Input: String="ppqp", Pattern="pq"Output: [1, 2]Explanation: The two anagrams of the pattern in the given string are "pq" and "qp".

Example 2:

Input: String="abbcabc", Pattern="abc"Output: [2, 3, 4]Explanation: The three anagrams of the pattern in the given string are "bca", "cab", and "abc".