Problem

Given a string s, return a new string containing the characters of s in reverse order. Implement the reversal without using built-in reverse helpers for strings, and aim for a linear-time solution.

Examples

Example 1:

Input: s = "hello"
Output: "olleh"
Explanation: Reversing the character order gives "olleh".

Example 2:

Input: s = "Autodesk"
Output: "ksedotuA"
Explanation: The first and last characters swap positions, continuing inward.

Constraints

• 0 <= len(s) <= 10^5
• s may contain letters, digits, spaces, and punctuation
• Return the reversed string with all characters preserved exactly