class Solution:

def wordPattern(self, pattern: str, s: str) -> bool:

words = s.split(" ")

pattern_ref = {}

value_ref = set()

# build pattern for reference

for i in list(pattern):

if i not in pattern_ref:

pattern_ref[i] = ""

if len(words) != len(pattern):

return False

# check the words

for w in range(len(words)):

word = words[w]

if pattern_ref[pattern[w]] == "" and word in value_ref:

return False

elif pattern_ref[pattern[w]] == "":

pattern_ref[pattern[w]] = word

value_ref.add(word)

elif pattern_ref[pattern[w]] == word:

continue

else:

return False

return True