Faulty Keyboard — LeetCode 2810 Python Solution

The problem

Your laptop keyboard is faulty, and whenever you type a character 'i' on it, it reverses the string that you have written. Typing other characters works as expected.

Example

Input

s = "string"

Output

"rtsng"

Explanation

After typing first character, the text on the screen is "s".

Python solution

class Solution:
    def finalString(self, s: str) -> str:
        t = []
        for c in s:
            if c == "i":
                t = t[::-1]
            else:
                t.append(c)
        return "".join(t)

Complexity

Pattern: Hash Map

Trade memory for time: remember what you have seen so the second pass never happens. LeetCode 2810. Faulty Keyboard is filed here because the reference solution below belongs to the algorithm family this hub collects, even though its LeetCode tags point elsewhere.

The hash map guide has the Python template for the pattern and the 709 LeetCode problems that use it.

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