def sherlockAndAnagrams(s):
    count = 0

    for window_size in range(1, len(s)):

        counter = _count(s[:window_size])
        snapshots = collections.defaultdict(lambda: 0)
        snapshot = tuple(counter.values())
        snapshots[snapshot] += 1

        for i in range(1, len(s) - window_size + 1):
            j = i + window_size - 1
            counter[s[i-1]] -= 1
            counter[s[j]] += 1

            snapshot = tuple(counter.values())
            count += snapshots[snapshot]
            snapshots[snapshot] += 1

    return count

def _count(s: str) -> dict[str, int]:
    counter = dict.fromkeys("abcdefghijklmnopqrstuvwxyz", 0)
    for char in s:
        counter[char] += 1
    return counte