Given a pattern and a string s, find if s follows the same pattern.
Here follow means a full match, such that there is a bijection between a letter in pattern and a non-empty word in s.
Input: pattern = "abba", s = "dog cat cat dog"
Output: true
Input: pattern = "abba", s = "dog cat cat fish"
Output: false
Input: pattern = "aaaa", s = "dog cat cat dog"
Output: false