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.