Permutation in String

Given two stringss1ands2, write a function to return true ifs2contains the permutation ofs1. In other words, one of the first string's permutations is thesubstringof the second string.

Example 1:

Input: 
s1 = "ab" s2 = "eidbaooo"

Output: 
True

Explanation:
 s2 contains one permutation of s1 ("ba").

Example 2:

Input:
s1= "ab" s2 = "eidboaoo"

Output:
 False

分析

模板，注意是作为Min在while里被比较， 比较len(s1) == e-s?

class Solution:
    def checkInclusion(self, s1: str, s2: str) -> bool:
        lss,ll,s,e,counter,mm = len(s1),len(s2),0,0,len(s1),collections.Counter(list(s1))
        while e < ll:
            if mm[s2[e]] > 0:
                counter -= 1
            mm[s2[e]] -= 1
            e += 1
            while counter == 0:
                if lss == e - s:
                    return True
                if mm[s2[s]] == 0:
                    counter += 1
                mm[s2[s]] += 1
                s += 1

        return False