# 438. Find All Anagrams in a String

## 1. Question

Given two strings s and p, return an array of all the start indices of p's anagrams in s. You may return the answer in any order.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

## 2. Examples

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".


## 3. Constraints

• 1 <= s.length, p.length <= 3 * 104
• s and p consist of lowercase English letters.

## 5. Solutions

class Solution {
public List<Integer> findAnagrams(String s, String p) {
List<Integer> ans = new ArrayList<>();

if (s.length() < p.length()) {
return ans;
}

int[] ps = new int[26];
int[] res = new int[26];
for (int i = 0; i < p.length(); i++) {
ps[p.charAt(i) - 'a']++;
}

int left = 0;
int right = p.length();

for (int i = 0; i < p.length(); i++) {
res[s.charAt(i) - 'a']++;
}

if (Arrays.equals(ps, res)) {
}

while (right < s.length()) {
res[s.charAt(right) - 'a']++;
right++;

res[s.charAt(left) - 'a']--;
left++;

if (Arrays.equals(ps, res)) {