3612 - Process String with Special Operations I.

Medium

You are given a string s consisting of lowercase English letters and the special characters: *, #, and %.

Build a new string result by processing s according to the following rules from left to right:

• If the letter is a lowercase English letter append it to result.

• A '*' removes the last character from result, if it exists.

• A '#' duplicates the current result and appends it to itself.

• A '%' reverses the current result.

Return the final string result after processing all characters in s.

Example 1:

Input: s = "a#b%\*"

Output: "ba"

Explanation:

Thus, the final result is "ba".

Example 2:

Input: s = "z\*#"

Output: ""

Explanation:

Thus, the final result is "".

Constraints:

• 1 <= s.length <= 20

• s consists of only lowercase English letters and special characters *, #, and %.