Reverse the character array s in place, using O(1) extra memory.
Example 1
Input: s = ["H","a","n","n","a","h"]
Output: ["h","a","n","n","a","H"]
Explanation: Reversal preserves the case of each character.
Output: ["h","a","n","n","a","H"]
Explanation: Reversal preserves the case of each character.
Example 2
Input: s = ["h","e","l","l","o"]
Output: ["o","l","l","e","h"]
Explanation: The character array is reversed in place.
Output: ["o","l","l","e","h"]
Explanation: The character array is reversed in place.