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 substring in
"abab", str =
"redblueredblue"should return true.
"aaaa", str =
"asdasdasdasd"should return true.
"aabb", str =
"xyzabcxzyabc"should return false.
You may assume both
str contains only lowercase letters.