Introduction

In this blog post, we will explore how to solve the LeetCode problem "1805" 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

You are given a string word that consists of digits and lowercase English letters. You will replace every non-digit character with a space. For example, "a123bc34d8ef34" will become " 123 34 8 34". Notice that you are left with some integers that are separated by at least one space: "123", "34", "8", and "34". Return the number of different integers after performing the replacement operations on word. Two integers are considered different if their decimal representations without any leading zeros are different. Example 1: Input: word = "a123bc34d8ef34" Output: 3 Explanation: The three different integers are "123", "34", and "8". Notice that "34" is only counted once. Example 2: Input: word = "leet1234code234" Output: 2 Example 3: Input: word = "a1b01c001" Output: 1 Explanation: The three integers "1", "01", and "001" all represent the same integer because the leading zeros are ignored when comparing their decimal values. Constraints: 1 <= word.length <= 1000 word consists of digits and lowercase English letters.

Explanation

• Isolate Integers: Iterate through the string, identifying contiguous sequences of digits. When a non-digit is encountered, treat the accumulated digits (if any) as a potential integer.
  • Remove Leading Zeros: Convert each extracted integer string to its numerical representation by removing any leading zeros to ensure that "01" and "1" are treated as the same.
  • Unique Count: Use a set to store the distinct numerical values encountered, ensuring that each unique integer is counted only once.

• Time Complexity: O(n), where n is the length of the input string.
• Space Complexity: O(k), where k is the number of unique integers in the string.

Code

    def numDifferentIntegers(word: str) -> int:
    """
    Given a string word that consists of digits and lowercase English letters.
    You will replace every non-digit character with a space.
    For example, "a123bc34d8ef34" will become " 123  34 8  34".
    Notice that you are left with some integers that are separated by at least one space: "123", "34", "8", and "34".
    Return the number of different integers after performing the replacement operations on word.
    Two integers are considered different if their decimal representations without any leading zeros are different.

    Constraints:
    1 <= word.length <= 1000
    word consists of digits and lowercase English letters.
    """

    nums = set()
    current_num = ""
    for char in word:
        if char.isdigit():
            current_num += char
        else:
            if current_num:
                nums.add(int(current_num))
                current_num = ""

    if current_num:
        nums.add(int(current_num))

    return len(nums)