Find the Losers of the Circular Game problem in Java

The Circular Game problem is a classic programming challenge that involves a group of people arranged in a circle. The goal is to find the losers of the game, wherein everybody eliminates the person subsequent to them in a clockwise path till the one person stays. In this section, we will explore how to resolve the Circular Game trouble using Java and offer step-by-step explanations along with code snippets and their outputs.

Problem Statement:

Given a number of players, we need to determine the losers of the Circular Game until only one person remains.

Approach:

To resolve the Circular Game problem, we can use a round linked list to symbolize the players. Each node in the linked list represents a participant, and the "next" pointer factors to the next participant inside the circle. We will start the game through eliminating the following participant till only one player is left.

Implementation:

Let's implement the Circular Game problem in Java step by step.

Step 1: Create a Player class

class Player {
    int id;
    Player next
    public Player(int id) {
        this.id = id;
    }
}

The Player class represents a player in the game. It has an id field to uniquely identify each player and a next field to store the reference to the next player.

Step 2: Create a CircularGame class

Let's consider an example where there are 5 players, and 2 players are eliminated in each round.

import java.util.Scanner;
class CircularGame {
    private Player head;
    public void createPlayers(int numPlayers) {
        Player prev = null;
        for (int i = 1; i <= numPlayers; i++) {
            Player player = new Player(i);
            if (prev != null) {
                prev.next = player;
            } else {
                head = player;
            }
            prev = player;
        }
        prev.next = head; // Connect the last player to the first player to form a circular linked list
    }
    public void eliminatePlayers(int numPlayers) {
        Player current = head;
        while (current.next != current) {
            for (int i = 1; i < numPlayers - 1; i++) {
                current = current.next;
            }
            System.out.println("Player " + current.next.id + " eliminated.");
            current.next = current.next.next;
            current = current.next;
        }
        System.out.println("Player " + current.id + " wins!");
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter the number of players: ");
        int numPlayers = scanner.nextInt();
        System.out.print("Enter the number of players to be eliminated in each round: ");
        int numEliminated = scanner.nextInt();
        CircularGame game = new CircularGame();
        game.createPlayers(numPlayers);
        game.eliminatePlayers(numEliminated);
        scanner.close();
    }
}

Output:

Enter the number of players: 5
Enter the number of players to be eliminated in each round: 2
Player 2 eliminated.
Player 4 eliminated.
Player 1 eliminated.
Player 5 eliminated.
Player 3 wins!

Explanation:

The createPlayers() method creates the circular linked list of players. It takes the number of players as input and assigns a unique ID to each player while maintaining the circular structure of the linked list. The eliminatePlayers() method performs the elimination process. It takes the number of players to be eliminated in each round as input. The current variable keeps track of the player whose turn it is to eliminate the next player. It traverses the linked list and removes the next player until only one player remains. In the main method, we take input from the user for the number of players and the number of players to be eliminated in each round. We create an instance of the CircularGame class, call the createPlayers() method to set up the game, and then call the eliminatePlayers() method to determine the winners and losers.

In this example, players 2 and 4 are eliminated in the first round, followed by players 1 and 5 in the second round. Finally, player 3 remains as the winner.

In this section, we have discussed how to solve the Circular Game problem in Java using a circular linked list. We have provided a step-by-step explanation of the approach and presented a complete Java implementation along with example output. The Circular Game problem is an interesting programming challenge that tests your understanding of linked lists and traversal algorithms. By following the implementation provided here, you can easily find the winners and losers of the Circular Game in Java.

Next TopicFinding the Differences Between Two Lists in Java

← prev next →