kotlin coding test course, 022 sorting numbers 3

Problem Description

This problem is an algorithmic problem of sorting a given sequence. Specifically,
you need to write a program that receives N integers as input, sorts
them in ascending order, and then prints each integer on a separate line.

Input Format

The first line contains an integer N (1 ≤ N ≤ 1,000,000).
The second line contains N integers, each of which is
between -1,000,000,000 and
1,000,000,000.

Output Format

Sort the input integers in ascending order and print each integer on
a separate line.

Approach to the Problem

To solve this problem, you can use an algorithm to sort the array.
Kotlin provides a powerful library function for array sorting by default.
However, due to the large size of numbers, attention must be paid to time complexity.
A special sorting algorithm should be applied for optimal performance.

Algorithm Selection

Given that the input size of the problem can go up to 1,000,000,
it is advisable to use efficient sorting algorithms like quicksort or
mergesort, which have a time complexity of O(N log N).
Additionally, in Kotlin, you can easily sort by utilizing the
sort() method from the standard library.

Code Implementation

Below is the solution code using Kotlin:

fun main() {
    val n = readLine()!!.toInt()  // Input N from the first line
    val numbers = IntArray(n)      // Create an integer array

    for (i in 0 until n) {
        numbers[i] = readLine()!!.toInt()  // Input the next N integers
    }

    numbers.sort()  // Perform sorting

    numbers.forEach { println(it) }  // Output the sorted numbers
}
    

Code Explanation

1. Use readLine()!!.toInt() to read integers from standard input.
Read the value of N from the first line and store all subsequent N integers in the
numbers array.

2. Use the numbers.sort() method to sort
the array in ascending order. This method uses
an efficient sorting algorithm internally.

3. Finally, print the sorted numbers line by line using
forEach.

Example of Results

Below is an example input and output after running this program:

Input:

5
5
2
3
1
4
    

Output:

1
2
3
4
5
    

Memory and Time Complexity

This algorithm has a time complexity of O(N log N). This is because
it sorts by dividing the input array size logarithmically.
Memory usage requires O(N) to store the array.

Summary of Problem-Solving Process

• Store all numbers given as input in an array.
• Sort the array in ascending order.
• Output the sorted result.

Conclusion

In this tutorial, we learned how to sort numbers using Kotlin.
You should practice solving algorithmic problems systematically to
derive correct results even with various inputs and conditions.

Keep enhancing your skills through different algorithmic problems!