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.

Examples: pattern = "abba", str = "dog cat cat dog" should return true. pattern = "abba", str = "dog cat cat fish" should return false. pattern = "aaaa", str = "dog cat cat dog" should return false. 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.

class Solution(object):
    def wordPattern(self, pattern, str):
        """
        :type pattern: str
        :type str: str
        :rtype: bool
        """
        d = {}
        str = str.split()
        if len(pattern) != len(str):
            return False
        for i in range(len(str)):
            if pattern[i] in d:
                if d[pattern[i]] != str[i]:
                    return False
            elif str[i] in d.values():
                return False
            else:
                d[pattern[i]] = str[i]
        return True

Trick:

class Solution(object):
    def wordPattern(self, pattern, str):
        """
        :type pattern: str
        :type str: str
        :rtype: bool
        """
        return map(pattern.find, pattern) == map(str.split().index, str.split())