Reverse String Leetcode Python Solution

Leetcode Question

Write a function that reverses a string. The input string is given as an array of characters s.

You must do this by modifying the input array in-place with O(1) extra memory.

Python Solution

class Solution:
    def reverseString(self, s: List[str]) -> None:
        """
        Do not return anything, modify s in-place instead.
        """
        l = 0
        r = len(s)-1
        while l<r:
            s[l],s[r] = s[r],s[l]
            l+=1
            r-=1