C# Coding Test Course, Card Game

Hello! In this post, we will explore one of the algorithm coding test problems using C#, the card game problem. I will explain in detail the concepts and approaches needed to solve algorithm problems.

Problem Description

You are designing a card game played between two players (A and B). The card deck consists of cards numbered from 1 to N. Each player has a unique set of cards, and each set consists of entirely unique cards. The rules of the game are as follows:

  • Both players select one card from their respective sets.
  • The numbers on the two cards are compared, and the owner of the higher card wins.
  • In case of a tie, Player A wins.

Given the card lists of Player A and Player B, write a program that determines the winner of each round and finally outputs the overall winner.

Input Format

The input is as follows:

  • The first line contains the number of cards N (1 ≤ N ≤ 1000).
  • The second line lists Player A’s cards separated by spaces.
  • The third line lists Player B’s cards separated by spaces.

Output Format

After printing the winner of each round, also print who the final winner is. For example:

    "A" (A's card, B's card)
    "B" (A's card, B's card)
    "A" (A's card, B's card)
    => Final Winner: A

Example Input

5
2 3 5 1 4
6 4 2 5 3

Example Output

B (2, 6)
A (3, 4)
A (5, 2)
A (1, 5)
B (4, 3)
=> Final Winner: A

Problem Analysis and Approach

To solve this problem, we will use a loop to compare the card numbers in each round. The principle is simple:

  1. We compare the lists of cards for Player A and Player B in order.
  2. We determine the winner for each pair of cards (Player A’s card, Player B’s card).
  3. We print the winner and use a count to determine the final winner.

C# Code Implementation


using System;
using System.Linq;

class CardGame
{
    static void Main()
    {
        // Input number of cards
        int N = int.Parse(Console.ReadLine());
        
        // Input Player A's cards
        int[] playerA = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
        
        // Input Player B's cards
        int[] playerB = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
        
        // Player win counts
        int scoreA = 0, scoreB = 0;

        // Conduct each round
        for (int i = 0; i < N; i++)
        {
            // Each player's card
            int cardA = playerA[i];
            int cardB = playerB[i];

            // Determine winner
            if (cardA > cardB)
            {
                Console.WriteLine($"A ({cardA}, {cardB})");
                scoreA++;
            }
            else if (cardB > cardA)
            {
                Console.WriteLine($"B ({cardA}, {cardB})");
                scoreB++;
            }
            else
            {
                Console.WriteLine($"A ({cardA}, {cardB})");
                scoreA++; // A wins in case of a tie
            }
        }

        // Determine final winner
        Console.WriteLine($"=> Final Winner: {(scoreA >= scoreB ? "A" : "B")}");
    }
}

Problem Solving Process

Let’s take a step-by-step look at the problem-solving process.

Step 1: Read Input

First, we read the number of cards and the card lists for Player A and B from user input. In C#, the Console.ReadLine() method is used to read input as a string. We separate the received string using the Split() method and convert it into an integer array using int.Parse().

Step 2: Compare Cards and Determine Winner

We handled each round using a loop. We compared the cards of Player A and B and printed the winner. We used simple conditional statements to compare the cards for determining the winner.

Step 3: Print Final Winner

After each round, we updated the win counts, and after all rounds were finished, we printed the final winner. We also used conditional statements to compare the final scores.

Complexity Analysis

The time complexity of this problem is O(N), where N is the number of cards. This is because the card lists given as input are examined only once. The space complexity is also O(N), as the amount of memory used to store the card lists is proportional to the number of cards N.

Additional Tips

It is essential to develop basic algorithmic thinking while solving this problem. You can enhance your algorithmic problem-solving skills through the following tips:

  • Clearly understand the conditions of the problem and simulate various cases through examples.
  • Before writing code, cultivate the habit of leaving comments on the flow of the algorithm.
  • Make an effort to solve the problems you’ve practiced in various ways. Different solutions may exist even for the same problem.

Conclusion

Solving algorithm problems using C# greatly helps in developing various thinking and problem-solving skills. I hope this post on the card game problem serves as a stepping stone for further advancement. I plan to share more algorithm problems and solutions, so please stay tuned!