Remove Prefix Strings

You are given a list of strings.

A string is considered a prefix string if it is a prefix of any other string in the list. Your task is to remove all prefix strings while preserving the order of strings in the input.

Input: A list of strings, input_list. Output: A list of strings, output_list, containing only the strings that are not prefixes of any other strings in the input. The output list must preserve the order of strings from the input.

Example 1: Input: ["a", "ab", "abc"] Output: ["abc"]

Example 2: Input: ["a", "bc", "ab", "abc hello"] Output: ["bc", "abc hello"]

Note: order must be preserved (e.g., returning ["abc hello", "bc"] is incorrect).

Follow-up:

• What if the list contains millions of strings? How do you optimize beyond O(n^2)?