[#5] KoreanCoding 101: binary addition, making B out of A

Another Friday, another chance to polish your Korean technical vocabulary skills!

Announcement: Due to some new exciting things happening in my private life, I will have to limit the number of challenges we will be going through from this day forward. I'll try to focus on choosing the ones that will introduce new vocabulary as much as possible.

Ready? Let's go!

Vocabulary

Nouns:

문자열 - string
이진수 - binary
소문자 - lowercase
대문자 - uppercase
합 - sum
순서 - order (of something)
두 이진수의 합 - the sum of two binary numbers
함수 - function
매개변수 - parameter
메소드 - method
길이 - length
제한사항 - constraints
입출력 예 - input-output examples
입출력 예 설명 - explanation of input-output examples
삼항 연산자 - ternary operator

Verbs:

의미하다 - to mean, to stand for
2에 1을 더하다 - to add 1 to 2
바꾸다 - to change
정렬하다 - to sort

Phrases:

[something]을/를 return 하도록 solution 함수를 완성해주세요.
Complete the solution function to return [something].

문자열 bin1과 bin2가 주어질 때...
given two strings bin1 and bin2...

Challenges

이진수 더하기

Description

이진수를 의미하는 두 개의 문자열 bin1과 bin2가 매개변수로 주어질 때, 두 이진수의 합을 return하도록 solution 함수를 완성해주세요.

제한사항

• return 값은 이진수를 의미하는 문자열입니다.

• 1 ≤ bin1, bin2의 길이 ≤ 10

• bin1과 bin2는 0과 1로만 이루어져 있습니다.

• bin1과 bin2는 "0"을 제외하고 0으로 시작하지 않습니다.

입출력 예

bin1	bin2	result
"10"	"11"	"101"
"1001"	"1111"	"11000"

입출력 예 설명

입출력 예 #1

• 10 + 11 = 101 이므로 "101" 을 return합니다.

입출력 예 #2

• 1001 + 1111 = 11000 이므로 "11000"을 return합니다.

Description:

이진수 더하기
Binary addition

이진수를 의미하는 두 개의 문자열 bin1과 bin2가 매개변수로 주어질 때,
Given two strings bin1 and bin2 which represent binary numbers,

두 이진수의 합을 return하도록 solution 함수를 완성해주세요.
complete the solution function to return the sum of these two binary numbers.

제한사항 (constraints):

• The return value should be a string representing a binary number.

• The length of bin1 and bin2 should be between 1 and 10 (inclusive).

• bin1 and bin2 are composed only of the digits 0 and 1.

• bin1 and bin2 should not start with "0" except when the string consists of a single "0".

입출력 예 (input-output examples):

#1: When bin1 = '10' and bin2 ='11', the result should be '101'.

입출력 예 설명 (explanation of input-output examples):

Based on the example #1: Since 10 + 11 = 101, we return "101".

JavaScript Solution

In short, we want to perform binary addition on the two binary numbers provided and return the result as a binary string.
To do that, we can use parseInt() to convert both bin1 and bin2 to their decimal equivalents and sum them. Then, we can use toString() to convert the decimal sum back into a binary string by using it with a base argument of 2.

function solution(bin1, bin2) {
    const sum = parseInt(bin1, 2) + parseInt(bin2, 2)
    return sum.toString(2)
}

---

A로 B 만들기

Description

문자열 before와 after가 매개변수로 주어질 때, before의 순서를 바꾸어 after를 만들 수 있으면 1을, 만들 수 없으면 0을 return 하도록 solution 함수를 완성해보세요.

제한사항

• 0 < before의 길이 == after의 길이 < 1,000

• before와 after는 모두 소문자로 이루어져 있습니다.

입출력 예

before	after	result
"olleh"	"hello"	1
"allpe"	"apple"	0

입출력 예 설명

입출력 예 #1

• "olleh"의 순서를 바꾸면 "hello"를 만들 수 있습니다.

입출력 예 #2

• "allpe"의 순서를 바꿔도 "apple"을 만들 수 없습니다.

Description:

A로 B 만들기
Making B out of A

문자열 before와 after가 매개변수로 주어질 때,
Given strings before and after as parameters,

before의 순서를 바꾸어 after를 만들 수 있으면 1을,
Complete the solution function to return 1 if before can be reordered to create after

만들 수 없으면 0을 return 하도록 solution 함수를 완성해보세요
and if it cannot be created, return 0.

제한사항 (constraints):

• The length of the before and after string is greater than 0 and less than 1,000 and the length of the before string is equal to the length of the after string.

• Both the before and after strings consist only of lowercase letters.

입출력 예 (input-output examples):

#1: When before = "olleh" and after = "hello" return 1.

#2: When before = "allpe" and after = "apple" return 0.

입출력 예 설명 (explanation of input-output examples):

Based on the example #1:

You can make "hello" by reversing the order of "olleh".

Based on the example #2:

Reversing the order of "allpe" does not make "apple".

JavaScript Solution

The easiest way to check if two strings consist of the same characters is to split the string into an array of individual characters because it allows us to manipulate and sort the characters easily. Then we sort the array of characters in ascending order and join the sorted array of characters back into a string for easy comparison.

Finally, we use a ternary operator (삼항 연산자) to return the correct result: if they match, we return 1 and if they do not, we return 0.

function solution(before, after) {
    const bMod = before.split("").sort().join("")
    const aMod = after.split("").sort().join("")
    return aMod === bMod ? 1 : 0
}

Wrap-up

And that's it for today! Awesome job!

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Have an awesome weekend!