leetcode/work/3/Easy/Two Pointers/344.reverse-string.py

"""
344. Reverse String
Difficulty: Easy
https://leetcode.com/problems/reverse-string/

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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.



Example 1:

Input: s = ["h","e","l","l","o"]
Output: ["o","l","l","e","h"]

Example 2:

Input: s = ["H","a","n","n","a","h"]
Output: ["h","a","n","n","a","H"]



Constraints:

        • 1 <= s.length <= 10^5

        • s[i] is a printable ascii character.
"""


class Solution:
    def reverseString(self, s: List[str]) -> None:
        l = 0
        r = len(s) - 1
        while l < r:
            s[l], s[r] = s[r], s[l]
            l += 1
            r -= 1

        """
        Do not return anything, modify s in-place instead.
        """