kotlin coding test course, sort numbers

Author: [Author Name]

Date: [Date]

Introduction

In coding tests, various problems are presented to evaluate algorithm problem-solving abilities. Among these, the “Sorting Numbers” problem is fundamental yet requires important algorithmic thinking. This problem aims to provide an opportunity to understand basic sorting algorithms and become familiar with the syntax of the Kotlin language.

Problem Description

Write a program to sort a given number of integers in ascending order.
The first line of input contains the integer N, followed by N lines each containing an integer.
Write a program that sorts these integers and outputs them one per line.

Input

        - The first line contains an integer N (1 ≤ N ≤ 1,000,000)
        - The next N lines each contain an integer A (1 ≤ A ≤ 1,000,000)

Output

        - Print the N integers sorted in ascending order, one per line

Problem Approach

This problem is a basic one that requires a sorting algorithm. Among various sorting algorithms,
utilizing the built-in features of Kotlin is useful.
We will solve the problem through the following steps.

  1. Receiving input
  2. Applying the sorting algorithm
  3. Outputting the sorted result

1. Receiving Input

In Kotlin, you can use the readLine() function to take standard input.
Read the integer N from the first line and store the next N integers in an array or list.

Below is an example code used for receiving input. 

            fun main() {
                val n = readLine()!!.toInt()
                val numbers = ArrayList()
                for (i in 1..n) {
                    numbers.add(readLine()!!.toInt())
                }
                // Following is sorting and output code
            }

2. Applying the Sorting Algorithm

In Kotlin, you can easily sort a list using the sorted() function.
This function sorts by default in ascending order, so it can be used without additional implementation.
You can apply sorting as follows. 

            val sortedNumbers = numbers.sorted()

3. Outputting the Sorted Result

To print the sorted list, you can use a loop.
Simply output each element one per line.
To do this, you can use the forEach function. 

            sortedNumbers.forEach { println(it) }

Complete Code

The complete code combining all the steps described above is as follows. 

            fun main() {
                val n = readLine()!!.toInt()
                val numbers = ArrayList()
                
                for (i in 1..n) {
                    numbers.add(readLine()!!.toInt())
                }

                val sortedNumbers = numbers.sorted()

                sortedNumbers.forEach { println(it) }
            }

Complexity Analysis

The time complexity of the sorting algorithm used in this problem is generally O(N log N).
Therefore, it can efficiently handle sorting up to 1,000,000 integers.

Conclusion

The “Sorting Numbers” problem is greatly helpful in learning basic algorithms and the syntax of Kotlin.
To solve algorithm problems, it’s important to solidify the basics and practice with various problems.
I hope you continue to learn and practice different algorithms to prepare thoroughly for coding tests.

Thank you!