[LeetCode] 438. Find All Anagrams in a String

438. Find All Anagrams in a StringAdd to List

Difficulty: Easy

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".

思路: 

1.先用 collection.Count() 把兩個字串都變成 字典

2.如果兩個字典相同 則把 index 加入結果的list. rtype

3.掃一遍 s 字串, 邊掃邊滑動 window. 一邊加一邊減 並重複步驟 2