Given a string s, return a new string containing the characters of s in reverse order. The input is a string and the output must also be a string. Solve it in linear time.
Example 1:
Input: s = "hello"
Output: "olleh"
Explanation: Reversing the characters of "hello" gives "olleh".
Example 2:
Input: s = "a b!"
Output: "!b a"
Explanation: Spaces and punctuation are reversed like any other character.
0 <= len(s) <= 10^5s may contain letters, digits, spaces, and punctuation