import math
from collections import Counter

class Solution:
  def findStringAnagrams(self, text, pattern):
    result = []
    if text == "":
      return result 

    # pattern frequency count
    pattern_counter = Counter(pattern)

    # initial window frequency count
    text_counter = {}
    for i in range(len(pattern)):
      text_counter[text[i]] = text_counter.get(text[i], 0)
      text_counter[text[i]] += 1

    i = len(pattern) - 1
    j = 0
    
    while i < len(text):
      # if counters match we have an anagram
      if text_counter == pattern_counter:
        result.append(j)
      
      # move i then add the i frequency to the map
      i += 1
      if i == len(text):
        break
      text_counter[text[i]] = text_counter.get(text[i], 0)
      text_counter[text[i]] += 1

      # remove the j frequency from the map then move j
      text_counter[text[j]] -= 1
      if text_counter[text[j]] == 0:
        del text_counter[text[j]]
      j += 1
      
    return result