"""
Maintain a sliding window of constant length s1. Keep adding from the right and removing from left from the hashmap counter
and compare the dictionary. If equal return True.
"""


class Solution:
    def checkInclusion(self, s1: str, s2: str) -> bool:

        counter_s1 = {}
        window_s2 = {}

        for c in s1:
            counter_s1[c] = counter_s1.get(c, 0) + 1

        left = 0
        for c in s2[:len(s1)-1]:
            window_s2[c] = window_s2.get(c, 0) + 1

        for right in range(len(s1)-1, len(s2)):
            window_s2[s2[right]] = window_s2.get(s2[right], 0) + 1

            if counter_s1 == window_s2:
                return True
            else:
                window_s2[s2[left]] = window_s2.get(s2[left], 0) - 1
                if window_s2[s2[left]] == 0:
                    window_s2.pop(s2[left])
                left = left + 1

        return False