Kotlin coding test course, sorting 1

Problem Description

In this lecture, we will discuss a simple sorting algorithm problem called “Sorting Numbers 1.” The task is to sort the given numbers in ascending order. The requirements of the problem are as follows:

Problem: An integer N is given. Write a program that sorts these numbers in ascending order and outputs one number per line.

Input Format

• The first line contains the integer N (1 ≤ N ≤ 100,000)
• From the second line, N integers are given. (The range of the numbers is -1,000,000,000 ≤ integer ≤ 1,000,000,000)

Output Format

Output the sorted numbers in ascending order, one per line.

Example Input

    5
    5
    4
    3
    2
    1
    

Example Output

    1
    2
    3
    4
    5
    

Process of Solving the Problem

To solve this problem, we need to use a sorting algorithm. Kotlin provides built-in sorting methods, making it easy to solve the problem. Below is the process of solving the problem.

1. Receiving Input

First, we need to receive input. We will read the integer N and the array of integers through standard input. In Kotlin, we can use the readLine() method to get input.

2. Creating the Number Array

We need to convert the input numbers into an integer array and store them. To do this, we use the split() method along with the map() method.

3. Sorting

To sort the organized number array in ascending order, we can use Kotlin’s sort() method. This is very efficient and intuitive.

4. Outputting the Results

To output the sorted array one by one, we can iterate through the array and print the values.

Code Implementation

Now let’s implement all these processes into a single Kotlin program. Below is the code that solves the problem.

fun main() {
        // 1. Receiving Input
        val n = readLine()!!.toInt()
        val numbers = IntArray(n)

        // 2. Creating the Number Array
        for (i in 0 until n) {
            numbers[i] = readLine()!!.toInt()
        }

        // 3. Sorting
        numbers.sort()

        // 4. Outputting the Results
        for (number in numbers) {
            println(number)
        }
    }

Code Explanation

The above code executes each step in order. First, it uses readLine()!!.toInt() to read the integer N from the first line, and then saves N integers into an array using a loop. After that, it calls numbers.sort() to sort the array, and finally prints the sorted results.

Efficiency

The time complexity of this algorithm is O(N log N). This is a characteristic performance of sorting algorithms, and it works well even for large datasets. Given that N can go up to 100,000 within the specified range, it is a sufficiently efficient solution.

Conclusion

In this lecture, we covered the basics of algorithm problem-solving using Kotlin through a simple number sorting problem. It is important to build foundational problem-solving skills before tackling more complex problems. Gaining experience by solving various problems is the best way to improve.

Thank you, and I hope this helps you prepare for your coding tests!