[567] Permutation in String

https://leetcode.com/problems/permutation-in-string/description/

• algorithms
• Medium (36.86%)
• Source Code: 567.permutation-in-string.py
• Total Accepted: 43.5K
• Total Submissions: 114.1K
• Testcase Example: '"ab"\n"eidbaooo"'

Given two strings s1 and s2, write a function to return true if s2 contains the permutation of s1. In other words, one of the first string's permutations is the substring of 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

Note:

The input strings only contain lower case letters.
The length of both given strings is in range [1, 10,000].

class Solution(object):
    def checkInclusion(self, s1, s2):
        """
        :type s1: str
        :type s2: str
        :rtype: bool
        """
        if not s1: return True
        len1 = len(s1)
        len2 = len(s2)
        if len1 > len2: return False

        S, V = [0]*26, [0]*26
        for i in range(len1):
            S[ord(s1[i])-ord('a')] += 1
            V[ord(s2[i])-ord('a')] += 1

        # print('S', S)
        for i in range(len1-1, len2):
            if S == V: return True
            if i == len1-1: continue
            else:
                V[ord(s2[i-len1])-ord('a')] -= 1
                V[ord(s2[i])-ord('a')] += 1
                # print('V', V)
                if S == V: return True

        return False


#
# s1 = "adc"
# s2 = "dcda"
# #
#
# s = Solution()
# print s.checkInclusion(s1, s2)
# print s1, s2