AssassinMain.java

import java.io.*;
import java.util.*;

/**
 * Class AssassinMain is the main client program for assassin game management.
 * It reads names from a file names.txt, shuffles them, and uses them to start
 * the game. The user is asked for the name of the next victim until the game is
 * over.
 */
public class AssassinMain {

    /**
     * input file name from which to read data
     */
    public static final String INPUT_FILENAME = "names.txt";

    /**
     * true for different results every run; false for predictable results
     */
    public static final boolean RANDOM = false;

    /**
     * If not random, use this value to guide the sequence of numbers that will
     * be generated by the Random object.
     */
    public static final int SEED = 42;

    public static void main(String[] args) throws FileNotFoundException {
        // read names into a Set to eliminate duplicates
        File inputFile = new File(INPUT_FILENAME);
        if (!inputFile.canRead()) {
            System.out.println("Required input file not found; exiting.\n" + inputFile.getAbsolutePath());
            System.exit(1);
        }
        Scanner input = new Scanner(inputFile);

        Set<String> names = new TreeSet<>(String.CASE_INSENSITIVE_ORDER);
        while (input.hasNextLine()) {
            String name = input.nextLine().trim().intern();
            if (name.length() > 0) {
                names.add(name);
            }
        }

        // transfer to an ArrayList, shuffle and build an AssassinManager
        ArrayList<String> nameList = new ArrayList<>(names);
        Random rand = (RANDOM) ? new Random() : new Random(SEED);
        Collections.shuffle(nameList, rand);

        AssassinManager manager = new AssassinManager(nameList);

        // prompt the user for victims until the game is over
        Scanner console = new Scanner(System.in);
        while (!manager.isGameOver()) {
            oneKill(console, manager);
        }

        // report who won
        System.out.println("Game was won by " + manager.winner());
        System.out.println("Final graveyard is as follows:");
        System.out.println(manager.graveyard());
    }

    /**
     * Handles the details of recording one victim. Shows the current kill ring
     * and graveyard to the user, prompts for a name and records the kill if the
     * name is legal.
     */
    public static void oneKill(Scanner console, AssassinManager manager) {
        // print both linked lists
        System.out.println("Current kill ring:");
        System.out.println(manager.killRing());
        System.out.println("Current graveyard:");
        System.out.println(manager.graveyard());

        // prompt for next victim to kill
        System.out.println();
        System.out.print("next victim? ");
        String name = console.nextLine().trim();

        // kill the victim, if possible
        if (manager.graveyardContains(name)) {
            System.out.println(name + " is already dead.");
        } else if (!manager.killRingContains(name)) {
            System.out.println("Unknown person.");
        } else {
            manager.kill(name);
        }
        System.out.println();
    }
}