Leetcode - Word Pattern Solution

# Leetcode - Word Pattern Solution

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:
def recreate(s):
index = 0
word_map = {}
for i in s:
x = word_map.get(i,-1)
if x!=-1:
yield x
else:
yield index
word_map[i] = index
index+=1
s = s.split()
if len(s) != len(pattern):
return False
return all(x==y for x,y in zip(recreate(pattern),recreate(s)))