from typing import List


def find_string_anagrams(str1: str, pattern: str) -> List[int]:
    """
    This problem follows the Sliding Window pattern and is very similar to Permutation in a String. In this problem, we
    need to find every occurrence of any permutation of the pattern in the string. We will use a list to store the
    starting indices of the anagrams of the pattern in the string.

    Time Complexity: O(N)
    Space Complexity: O(N)

    Parameters
    ----------
    str1 : str
        input string
    pattern : str
        input pattern

    Returns
    -------
    result : List[int]
        the list of starting indices of the anagrams of the pattern in the given string

    """
    matched = 0
    result = []
    seen = {}
    window_start = 0
    for char in pattern:
        if char not in seen:
            seen[char] = 1
        else:
            seen[char] += 1
    for window_end in range(len(str1)):
        right_char = str1[window_end]
        if right_char in seen:
            seen[right_char] -= 1
            if seen[right_char] == 0:
                matched += 1
        if matched == len(seen):
            result.append(window_start)
        if window_end >= len(pattern) - 1:
            left_char = str1[window_start]
            if left_char in seen:
                if seen[left_char] == 0:
                    matched -= 1
                seen[left_char] += 1
            window_start += 1
    return result