Find All Anagrams in a String (#438)
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.
Company Tags: Amazon, Facebook
Core Concept: Sliding Window, Hashing