1880-CheckIfWordEqualsSummationOfTwoWords.go

package main

// 1880. Check if Word Equals Summation of Two Words
// 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.

import "fmt"

func isSumEqual(firstWord string, secondWord string, targetWord string) bool {
    calc := func(s string) int {
        n := len(s)
        res := int(s[0] - 'a')
        for i := 1; i < n; i++ {
            res = (res * 10) + int(s[i] - 'a')
        }
        return res
    }
    // fmt.Println(calc(firstWord), " , ", calc(secondWord), " , ", calc(targetWord))
    return (calc(firstWord) + calc(secondWord)) == calc(targetWord)
}

func main() {
    // 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.
    fmt.Println(isSumEqual("acb", "cba", "cdb")) // true
    // 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.
    fmt.Println(isSumEqual("aaa", "a", "aab")) // false
    // 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.
    fmt.Println(isSumEqual("aaa", "a", "aaaa")) // true
}