Leetcode学习（41）—— Find All Anagrams in a String

Given a string s and a non-empty string p, find all the start indices of p’s anagrams in s.

Strings consists of lowercase English letters only and the length of both strings s and p will not be larger than 20,100.

The order of output does not matter.

Example 1:Input:s: "cbaebabacd" p: "abc"Output:[0, 6]Explanation:The substring with start index = 0 is "cba", which is an anagram of "abc".The substring with start index = 6 is "bac", which is an anagram of "abc".Example 2:Input:s: "abab" p: "ab"Output:[0, 1, 2]Explanation:The substring with start index = 0 is "ab", which is an anagram of "ab".The substring with start index = 1 is "ba", which is an anagram of "ab".The substring with start index = 2 is "ab", which is an anagram of "ab".

策略：

在沿着 字符串 s 滑动的过程中，检查从当前位置 i 到前方位置 i-len(p)+1 的 Counter 与 pCounter 的关系：

• 若相等，则将 前方位置 i-len(p)+1 的下标 存入 anagram_list
• 否则，将 前方位置 的字符的 数量 -1， 若该数量 == 0， 则从 sCounter 中删除该 字符