Reverse String

Description

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 <= 105 s[i] is a printable ascii character.

Solution

class Solution(object):
    def reverseString(self, s):
        """
        :type s: List[str]
        :rtype: None Do not return anything, modify s in-place instead.
        """
        for i in range(len(s)//2):
            x,y = s[i],s[-(i+1)]
            s[i],s[-(i+1)] = y,x

.