Explanation:The characters at the start and end are swapped: 'h' with 'o', then 'e' with 'l'. The middle 'l' remains in place. The array becomes ["o","l","l","e","h"].
Example 2:
Input:s = ["H","a","n","n","a","h"]
Output:["h","a","n","n","a","H"]
Explanation:The characters at the start and end are swapped: 'H' with 'h', then 'a' with 'a', then 'n' with 'n'. The array becomes ["h","a","n","n","a","H"].