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Ha Anna
Ha Anna

Posted on • Originally published at blog.haanna.com

[#1] KoreanCoding 101: Basic math (기초 수학)

Let's start with a short announcement: A new post for this series will be published every Friday, and depending on the complexity of the challenges, I'll aim to cover around 2-4 of them.

Now, let's get into it! 💫

Do you enjoy math? If not, don't worry! The math we'll be covering today is something that most of us encounter in our daily lives.

Vocabulary

Nouns:

덧셈 - addition

뺄셈 - subtraction

곱셈 - multiplication

나눗셈 - division

나머지 - remainder (modulo)

합 - sum, total

차 - difference

곱 - product (multiplication)

정수 - integer (a whole number, e.g. 3)

분수 - fraction (a part of a whole, e.g. 0.5)

몫 - quotient (the integer part of a division)

함수 - function

매개변수 - parameter

제한사항 - constraints

입출력 예 - input-output examples

입출력 예 설명 - explanation of input-output examples

Verbs:

2에 1을 더하다 - to add 1 to 2

2에 1을 추가하다 - to add 1 to 2

2에 1을 빼다 - to subtract 1 from 2

2에 1를 곱하다 - to multiply 2 by 1

1을 2로 나누다 - to divide 1 by 2

Phrases:

[something]을/를 return 하도록 solution 함수를 완성해주세요.

Complete the solution function to return [something].

정수 num1과 num2가 주어질 때...

given two integers num1 and num2...

num1과 num2의 합

the sum of num1 and num2

num1에서 num2를 뺀 값

the value obtained by subtracting num2 from num1

num1과 num2를 곱한 값

the value obtained by multiplying num1 by num2

num1을 num2로 나눈 값

the value obtained by dividing num1 by num2

num1을 num2로 나눈 몫

the result of dividing num1 by num2

num1를 num2로 나눈 나머지

the remainder (modulo) of dividing num1 by num2

Challenges

두 수의 합

Description

정수 num1num2가 주어질 때, num1num2을 return하도록 solution 함수를 완성해주세요.

제한사항

  • -50,000 ≤ num1 ≤ 50,000

  • -50,000 ≤ num2 ≤ 50,000

입출력 예

num1 num2 result
2 3 5
100 2 102

입출력 예 설명

입출력 예 #1

  • num1이 2이고 num2가 3이므로 2 + 3 = 5를 return합니다.

입출력 예 #2

  • num1이 100이고 num2가 2이므로 100 + 2 = 102를 return합니다.

Description:

When we look at the description of this challenge, we can already see some familiar words and phrases. Typically, coding challenges start by outlining the parameters that will be provided.

두 수의 합

The sum of two numbers

정수 num1 num2가 주어질 때

Given two integers num1 and num2,

num1 num2의 합을 return하도록 solution 함수를 완성해주세요.

complete the solution function to return the sum of num1 and num2.

제한사항 (constraints):

The constraints section of the challenge informs us that both num1 and num2 can have values ranging from -50,000 to 50,000.

입출력 예 (input-output examples):

Examples are a valuable tool for understanding the challenge description. In this case, we are provided with two input-output examples, which illustrate the given integers and the expected output from the solution function.

When num1 = 2 and num2 = 3 result should be 5.

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

This section provides a detailed explanation of how the input-output process works for each example. For instance, in the given example where num1 = 2 and num2 = 3, we can read:

num1이 2이고 num2가 3이므로 2 + 3 = 5를 return합니다.

Since num1 is 2 and num2 is 3, the function returns 2 + 3 = 5.

JavaScript Solution

And now we know exactly what to do and we can complete our solution function.

function solution(num1, num2) {
    return num1 + num2
}
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두 수의 차

Description

정수 num1num2가 주어질 때, num1에서 num2뺀 값을 return하도록 solution 함수를 완성해주세요.

제한사항

  • -50000 ≤ num1 ≤ 50000

  • -50000 ≤ num2 ≤ 50000

입출력 예

num1 num2 result
2 3 -1
100 2 98

입출력 예 설명

입출력 예 #1

  • num1이 2이고 num2가 3이므로 2 - 3 = -1을 return합니다.

입출력 예 #2

  • num1이 100이고 num2가 2이므로 100 - 2 = 98을 return합니다.

Description:

This challenge is pretty similar to the last one, so let's dive straight into it!

두 수의 차

The difference between the two numbers

정수 num1 num2가 주어질 때,

Given two integers num1 and num2,

num1에서 num2를 뺀 값을 return하도록 solution 함수를 완성해주세요.

complete the solution function to return the value obtained by subtracting num2 from num1.

제한사항 (constraints):

The constraints section of the challenge informs us that both num1 and num2 can have values ranging from -50,000 to 50,000.

입출력 예 (input-output examples):

When num1 = 2 and num2 = 3 result should be -1.

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

Based on the example #1:

num1이 2이고 num2가 3이므로 2 - 3 = -1을 return합니다.

Since num1 is 2 and num2 is 3, the function returns 2 - 3 = -1.

JavaScript Solution

function solution(num1, num2) {
    return num1 - num2
}
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두 수의 곱

Description

정수 num1, num2매개변수 주어집니다. num1num2곱한 값을 return 하도록 solution 함수를 완성해주세요.

제한사항

  • 0 ≤ num1 ≤ 100

  • 0 ≤ num2 ≤ 100

입출력 예

num1 num2 result
3 4 12
27 19 513

입출력 예 설명

입출력 예 #1

  • num1이 3, num2가 4이므로 3 * 4 = 12를 return합니다.

입출력 예 #2

  • num1이 27, num2가 19이므로 27 * 19 = 513을 return합니다.

Description:

두 수의 곱

The product of two numbers

정수 num1, num2가 매개변수 주어집니다.

Integers num1, num2 are given as parameters.

num1 num2를 곱한 값을 return 하도록 solution 함수를 완성해주세요.

Complete the solution function to return the value obtained by multiplying num1 by num2.

제한사항 (constraints):

The constraints section of the challenge informs us that both num1 and num2 can have values ranging from 0 to 100.

입출력 예 (input-output examples):

When num1 = 3 and num2 = 4 result should be 12.

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

Based on the example #1:

num1이 3, num2가 4이므로 3 * 4 = 12를 return합니다.

Since num1 is 3 and num2 is 4, the function returns 3 * 4 = 12.

JavaScript Solution

function solution(num1, num2) {
    return num1 * num2
}
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두 수의 나눗셈

Description

정수 num1num2매개변수로 주어질 때, num1num2로 나눈 값에 1,000을 곱한 후 정수 부분을 return 하도록 solution 함수를 완성해주세요.

제한사항

  • 0 < num1 ≤ 100

  • 0 < num2 ≤ 100

입출력 예

num1 num2 result
3 2 1500
7 3 2333
1 16 62

입출력 예 설명

입출력 예 #1

  • num1이 3, num2가 2이므로 3 / 2 = 1.5에 1,000을 곱하면 1500이 됩니다.

입출력 예 #2

  • num1이 7, num2가 3이므로 7 / 3 = 2.33333...에 1,000을 곱하면 2333.3333.... 이 되며, 정수 부분은 2333입니다.

입출력 예 #3

  • num1이 1, num2가 16이므로 1 / 16 = 0.0625에 1,000을 곱하면 62.5가 되며, 정수 부분은 62입니다.

Description:

두 수의 나눗셈

The division of two numbers

정수 num1 num2가 매개변수로 주어질 때,

Integers num1 and num2 are given as parameters,

num1 num2로 나눈 값에 1,000을 곱한 후 정수 부분을 return 하도록 solution 함수를 완성해주세요.

First divide num1 by num2 and then multiply the resulting value by 1000. To complete the solution function, the returned value should always be an integer.

제한사항 (constraints):

The constraints section of the challenge informs us that both num1 and num2 can have values ranging from 0 to 100.

입출력 예 (input-output examples):

Example #1:

When num1 = 3 and num2 = 2 result should be 1500.

Example #2:

When num1 = 7 and num2 = 3 result should be 2333.

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

Based on the example #1:

num1이 3, num2가 2이므로 3 / 2 = 1.5에 1,000을 곱하면 1500이 됩니다.

Since num1 is 3 and num2 is 2, 3 / 2 = 1.5 multiplied by 1,000 is 1500.

Based on the example #2:

num1이 7, num2가 3이므로 7 / 3 = 2.33333...에 1,000을 곱하면 2333.3333.... 이 되며, 정수 부분은 2333입니다.

Since num1 is 7 and num2 is 3, 7/3 = 2.33333... Multiplied by 1,000 it is 2333.333... The integer part is 2333.

JavaScript Solution

In this challenge, simply dividing and multiplying will not be enough since it will give us a repeating decimal when we are required to return just the integer. To return the correct solution, we can wrap (num1/num2)*1000 in Math.floor(), which will return the largest integer that is less than or equal to a given number.

function solution(num1, num2) {
    return Math.floor((num1/num2) * 1000)
}
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나머지 구하기

Description

정수 num1, num2매개변수로 주어질 때, num1num2로 나눈 나머지를 return 하도록 solution 함수를 완성해주세요.

제한사항

  • 0 < num1 ≤ 100

  • 0 < num2 ≤ 100

입출력 예

num1 num2 result
3 2 1
10 5 0

입출력 예 설명

입출력 예 #1

  • num1이 3, num2가 2이므로 3을 2로 나눈 나머지 1을 return 합니다.

입출력 예 #2

  • num1이 10, num2가 5이므로 10을 5로 나눈 나머지 0을 return 합니다.

Description:

나머지 구하기

Finding the rest

정수 num1, num2가 매개변수로 주어질 때,

Given two integers num1 and num2,

num1 num2로 나눈 나머지를 return 하도록 solution 함수를 완성해주세요.

Complete the solution function to return the remainder (modulo) of num1 by num2.

제한사항 (constraints):

The constraints section of the challenge informs us that both num1 and num2 can have values ranging from 0 to 100.

입출력 예 (input-output examples):

When num1 = 3 and num2 = 2 result should be 1.

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

Based on the example #1:

num1이 3, num2가 2이므로 3을 2로 나눈 나머지 1을 return 합니다.

Since num1 is 3 and num2 is 2, 3 is divided by 2 and the remainder is 1.

JavaScript Solution

If you don't remember how the remainder works, you can read all about it here.

We will use the % symbol in our solution function, as it represents the remainder in computer languages.

function solution(num1, num2) {
    return num1 % num2
}
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몫 구하기

Description

정수 num1, num2매개변수로 주어질 때, num1num2나눈 몫을 return 하도록 solution 함수를 완성해주세요.

제한사항

  • 0 < num1 ≤ 100

  • 0 < num2 ≤ 100

입출력 예

num1 num2 result
10 5 2
7 2 3

입출력 예 설명

입출력 예 #1

  • num1이 10, num2가 5이므로 10을 5로 나눈 몫 2를 return 합니다.

입출력 예 #2

  • num1이 7, num2가 2이므로 7을 2로 나눈 몫 3을 return 합니다.

Description:

몫 구하기

Finding quotient (the integer part of a division)

정수 num1, num2가 매개변수로 주어질 때, 

Integers num1, num2 are given as parameters,

num1 num2로 나눈 몫을 return 하도록 solution 함수를 완성해주세요.

Complete the solution function by returning the integer part of a division of num1 by num2.

제한사항 (constraints):

The constraints section of the challenge informs us that both num1 and num2 can have values ranging from 0 to 100.

입출력 예 (input-output examples):

When num1 = 10 and num2 = 5 result should be 2.

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

For example #1:

num1이 10, num2가 5이므로 10을 5로 나눈 몫 2를 return 합니다.

Since num1 is 10 and num2 is 5, 10 divided by 5 returns the quotient of 2.

JavaScript Solution

Here again, since some of the divisions will give us a repeating decimal. To return just an integer, we can simply use Math.floor().

function solution(num1, num2) {
    return Math.floor(num1/num2)
}
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Wrap-up

Thank you for following along with this lesson! I hope you found it helpful. Remember, it's important to take things at your own pace and gradually build your skills when it comes to solving coding challenges, especially if you are also learning a new language. Building a strong technical Korean foundation is essential for tackling more complex challenges with ease.

Next week, we'll dive into topics that go beyond basic math, such as if/else statements, booleans, ternary operators, and more! I look forward to continuing this learning journey with you.

In the meantime, I hope you all have a fantastic weekend!

I'll see you next Friday!

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