290 Word Pattern
Given a pattern and a string str, find if str 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 str.
Input: pattern = "abba", str = "dog cat cat dog"
Input:pattern = "abba", str = "dog cat cat fish"
Input: pattern = "aaaa", str = "dog cat cat dog"
Input: pattern = "abba", str = "dog dog dog dog"
You may assume pattern contains only lowercase letters,
and str contains lowercase letters that may be separated by a single space.
If the one-to-one mapping cannot be established, return false directly.
It also returns false when the mapping values of the two HashMaps are not the same.