Introduction

In this blog post, we will explore how to solve the LeetCode problem "3330" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like Chatmagic, we can generate solutions quickly and efficiently - helping you pass the interviews and get the job offer without having to study for months.

Problem Statement

Alice is attempting to type a specific string on her computer. However, she tends to be clumsy and may press a key for too long, resulting in a character being typed multiple times. Although Alice tried to focus on her typing, she is aware that she may still have done this at most once. You are given a string word, which represents the final output displayed on Alice's screen. Return the total number of possible original strings that Alice might have intended to type. Example 1: Input: word = "abbcccc" Output: 5 Explanation: The possible strings are: "abbcccc", "abbccc", "abbcc", "abbc", and "abcccc". Example 2: Input: word = "abcd" Output: 1 Explanation: The only possible string is "abcd". Example 3: Input: word = "aaaa" Output: 4 Constraints: 1 <= word.length <= 100 word consists only of lowercase English letters.

Explanation

Here's a breakdown of the approach and the code:

• Identify Consecutive Repeats: The core idea is to iterate through the string and identify consecutive repeating characters.
• Count Possibilities: For each run of repeating characters, the number of possible original strings increases by the length of that run, since Alice could have intended to type the character any number of times from once to the length of the run.

• Sum Up: Finally, sum up all the possibilities calculated from these repeating sequences. If there are no repeating sequences, the answer is 1.

• Runtime Complexity: O(n), where n is the length of the word. Storage Complexity: O(1).

Code

    def possible_original_strings(word: str) -> int:
    """
    Calculates the total number of possible original strings Alice might have intended to type.

    Args:
        word: The final output displayed on Alice's screen.

    Returns:
        The total number of possible original strings.
    """

    n = len(word)
    if n == 0:
        return 0

    count = 1
    i = 0
    while i < n:
        j = i
        while j < n and word[i] == word[j]:
            j += 1

        if j - i > 1:
            count += j - i - 1

        i = j

    return count