determine_if_string_halves_are_alike.py

# You are given a string s of even length. Split this string into two halves of equal lengths, and let a be the first half and b 
# be the second half.

# Two strings are alike if they have the same number of vowels ('a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'). Notice that s 
# contains uppercase and lowercase letters.

# Return true if a and b are alike. Otherwise, return false.

 

# Example 1:

# Input: s = "book"
# Output: true
# Explanation: a = "bo" and b = "ok". a has 1 vowel and b has 1 vowel. Therefore, they are alike.
# Example 2:

# Input: s = "textbook"
# Output: false
# Explanation: a = "text" and b = "book". a has 1 vowel whereas b has 2. Therefore, they are not alike.
# Notice that the vowel o is counted twice.

class Solution:
    def halvesAreAlike(self, s: str) -> bool:
        vowels = 'aeiouAEIOU'
        indexer = 0
        
        reached_mid = False
        for i in range(len(s)):
            if i == len(s)//2:
                reached_mid = True
            if vowels.find(s[i]) != -1:
                if reached_mid:
                    indexer -= 1
                else:
                    indexer += 1
        
        return indexer == 0