Problem

At Notion, a text utility needs a function that returns a string with its characters reversed. Given a string s, write a function that returns a new string containing the characters of s in reverse order.

Formal Specification

• Input: a string s
• Output: a string representing s reversed
• The function should preserve all characters exactly, including spaces, punctuation, digits, and case.

Examples

Example 1

• Input: s = "hello"
• Output: "olleh"
• Explanation: The characters are returned from last to first.

Example 2

• Input: s = "Data 123"
• Output: "321 ataD"
• Explanation: Letters, digits, and spaces are all reversed as characters.

Constraints

• 0 <= len(s) <= 10^5
• s may contain uppercase letters, lowercase letters, digits, spaces, punctuation, and Unicode characters

Notes

You may assume the input is a valid string. Aim for a solution that runs in linear time. If you choose to build the result manually, avoid repeatedly concatenating immutable strings inside a loop, since that can be less efficient for large inputs.