290. Word Pattern-单词规律

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.

Example 1:
Input: pattern = "abba", s = "dog cat cat dog"
Output: true

Example 2:
Input: pattern = "abba", s = "dog cat cat fish"
Output: false

Example 3:
Input: pattern = "aaaa", s = "dog cat cat dog"
Output: false

Example 4:
Input: pattern = "abba", s = "dog dog dog dog"
Output: false

Constraints:

• 1 <= pattern.length <= 300
• pattern contains only lower-case English letters.
• 1 <= s.length <= 3000
• s contains only lower-case English letters and spaces ‘ ‘.
• s does not contain any leading or trailing spaces.
• All the words in s are separated by a single space.

Solution in python:

class Solution:
    def wordPattern(self, pattern: str, s: str) -> bool:
        alist = s.split(" ")
        if len(alist) != len(pattern):
            return False
        adic = dict()
        bdic = dict()
        for i in range(len(pattern)):
            bool1 = pattern[i] not in adic.keys()
            bool2 = alist[i] not in bdic.keys()
            if bool1 and bool2:
                adic[pattern[i]] = alist[i]
                bdic[alist[i]] = pattern[i]
            elif bool1 or bool2:
                return False
            elif adic[pattern[i]] != alist[i]:
                return False                     
        return True