In the process of preparing for coding tests using Kotlin, one of the problems many face is understanding and solving various algorithmic problems. In this course, we will learn how to easily understand and solve problems based on ancient narratives related to Jumong by solving an economical algorithm problem titled ‘Jumong’s Command’.<\/p>\n
Jumong commanded his army to defeat the enemies in the north and establish his kingdom. His command instructed each soldier to take a specific action. In this problem, when there are N soldiers, we need to determine what action each soldier will take.<\/p>\n
The problem is as follows:<\/p>\n
\nJumong has N soldiers. Each soldier is represented by a random number from 1 to 100, and Jumong commands soldiers with even numbers to “Move forward!” and those with odd numbers to “Step back!”.<\/p>\n
Write a program that counts the number of even and odd soldiers from the given list of N soldier numbers and outputs each command.<\/p>\n<\/blockquote>\n
Input<\/h2>\n
\n The first line contains the number of soldiers N (1 \u2264 N \u2264 1000).\n The second line contains N soldier numbers separated by spaces.\n <\/pre>\nOutput<\/h2>\n
\n Print the commands based on each soldier's even\/odd status.\n Output \"Move forward!\" or \"Step back!\" over N lines.\n <\/pre>\nExample Input<\/h2>\n
\n5\n1 2 3 4 5\n <\/pre>\nExample Output<\/h2>\n
\nStep back!\nMove forward!\nStep back!\nMove forward!\nStep back!\n <\/pre>\nProblem Solving Process<\/h2>\n
Now let’s look at how to solve this problem step by step. We will use Kotlin to solve it.<\/p>\n
Step 1: Get Input<\/h3>\n
First, we need to receive input from the user. We can use the
readLine()<\/code> function to get the input values.<\/p>\nStep 2: Convert to Number List<\/h3>\n
Since the entered numbers are separated by spaces, we need to convert them into a list. We will use Kotlin’s
split()<\/code> method to split by spaces.<\/p>\nStep 3: Determine Even\/Odd and Print Commands<\/h3>\n
Now, we can loop through all soldiers, check whether each number is even or odd, and print the corresponding command. We can use Kotlin’s
if<\/code> statement to evaluate the conditions.<\/p>\nCode Example<\/h2>\n
\nfun main() {\n \/\/ Step 1 - Get Input\n val n = readLine()!!.toInt() \/\/ Number of soldiers\n val soldiers = readLine()!!.split(\" \").map { it.toInt() } \/\/ List of soldier numbers\n\n \/\/ Step 3 - Determine Even\/Odd and Print Commands\n for (soldier in soldiers) {\n if (soldier % 2 == 0) {\n println(\"Move forward!\")\n } else {\n println(\"Step back!\")\n }\n }\n}\n <\/pre>\nSummary of the Entire Process<\/h2>\n
The process of solving the problem can be summarized as follows:<\/p>\n