Introduction

In this blog post, we will explore how to solve the LeetCode problem "1880" 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

The letter value of a letter is its position in the alphabet starting from 0 (i.e. 'a' -> 0, 'b' -> 1, 'c' -> 2, etc.). The numerical value of some string of lowercase English letters s is the concatenation of the letter values of each letter in s, which is then converted into an integer. For example, if s = "acb", we concatenate each letter's letter value, resulting in "021". After converting it, we get 21. You are given three strings firstWord, secondWord, and targetWord, each consisting of lowercase English letters 'a' through 'j' inclusive. Return true if the summation of the numerical values of firstWord and secondWord equals the numerical value of targetWord, or false otherwise. Example 1: Input: firstWord = "acb", secondWord = "cba", targetWord = "cdb" Output: true Explanation: The numerical value of firstWord is "acb" -> "021" -> 21. The numerical value of secondWord is "cba" -> "210" -> 210. The numerical value of targetWord is "cdb" -> "231" -> 231. We return true because 21 + 210 == 231. Example 2: Input: firstWord = "aaa", secondWord = "a", targetWord = "aab" Output: false Explanation: The numerical value of firstWord is "aaa" -> "000" -> 0. The numerical value of secondWord is "a" -> "0" -> 0. The numerical value of targetWord is "aab" -> "001" -> 1. We return false because 0 + 0 != 1. Example 3: Input: firstWord = "aaa", secondWord = "a", targetWord = "aaaa" Output: true Explanation: The numerical value of firstWord is "aaa" -> "000" -> 0. The numerical value of secondWord is "a" -> "0" -> 0. The numerical value of targetWord is "aaaa" -> "0000" -> 0. We return true because 0 + 0 == 0. Constraints: 1 <= firstWord.length, secondWord.length, targetWord.length <= 8 firstWord, secondWord, and targetWord consist of lowercase English letters from 'a' to 'j' inclusive.

Explanation

Here's a breakdown of the solution and the Python code:

• High-Level Approach:

  • Convert each string (firstWord, secondWord, targetWord) into its corresponding numerical value. This is done by iterating through the string and calculating the numerical representation as an integer.
  • Check if the sum of the numerical values of firstWord and secondWord is equal to the numerical value of targetWord.
  • Return True if they are equal, and False otherwise.

• Complexity:

  • Runtime Complexity: O(n), where n is the maximum length of the input strings.
  • Storage Complexity: O(1) - constant extra space.

Code

    def isSumEqual(firstWord: str, secondWord: str, targetWord: str) -> bool:
    """
    Checks if the sum of the numerical values of firstWord and secondWord equals the numerical value of targetWord.
    """

    def get_numerical_value(word: str) -> int:
        """
        Calculates the numerical value of a string.
        """
        numerical_value = 0
        for char in word:
            numerical_value = numerical_value * 10 + (ord(char) - ord('a'))
        return numerical_value

    first_value = get_numerical_value(firstWord)
    second_value = get_numerical_value(secondWord)
    target_value = get_numerical_value(targetWord)

    return first_value + second_value == target_value