Leetcode 290 Word Pattern

Posted 2020-07-28 Fourth Dimension

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.

Examples:

1. pattern = "abba", str = "dog cat cat dog" should return true.
2. pattern = "abba", str = "dog cat cat fish" should return false.
3. pattern = "aaaa", str = "dog cat cat dog" should return false.
4. pattern = "abba", str = "dog dog dog dog" should return false.

 

Notes:
You may assume pattern contains only lowercase letters, and str contains lowercase letters separated by a single space.

首先检验长度是否一致

然后判断每个map关系是否唯一对应

class Solution(object):
    def wordPattern(self, pattern, str):
        str = str.split(‘ ‘)
        if len(pattern) != len(str):
            return False
        h = {}
        for i in range(len(str)):
            if not h.has_key(pattern[i]):
                if str[i] not in h.values():
                    h[pattern[i]] = str[i]
                else:
                    return False
            else:
                if h[pattern[i]] != str[i]:
                    return False
        return True