[Leetcode/438A/Python] Find All Anagrams in a String #python #slidingwindow

Leetcode_438_SolutionA.py

class Solution:
    def findAnagrams(self, s: str, p: str) -> List[int]:
        result = []
        if len(s) < len(p):
            return result

        s_freq = [0 for _ in range(26)]
        p_freq = [0 for _ in range(26)]

        for i in range(len(p)):
            s_freq[ord(s[i]) - ord('a')] += 1
            p_freq[ord(p[i]) - ord('a')] += 1
        
        if s_freq == p_freq:
            result.append(0)

        for i in range(len(p), len(s)):
            s_freq[ord(s[i - len(p)]) - ord('a')] -= 1
            s_freq[ord(s[i]) - ord('a')] += 1
            if s_freq == p_freq:
                result.append(i - len(p) + 1)
        return result