Description: Reverse Prefix of Word

Code:

def reversePrefix(self, word: str, ch: str) -> str:
        if len(word) == 1:
            return word

        if ch not in word:
            return word

        left = 0
        right = word.index(ch)
        result = list(word)
        
        while left < right:
            result[left], result[right] = result[right], result[left]
            left += 1
            right -= 1

        return ''.join(result)

Efficiency:

Time Complexity: O(n)

Space Complexity: O(n)

Test:

assert reversePrefix("abcdefd", "d") == "dcbaefd"
assert reversePrefix("xyxzxe", "z") == "zxyxxe"
assert reversePrefix("abcd", "z") == "abcd"  # ch not found
assert reversePrefix("a", "a") == "a" # single character