JAVA

In class Scoreboard, add the following methods to it:

reverse(): it will reverse the entries on the scoreboard;

removeDuplicates(): it will remove all the duplicate entries on the scoreboard.

You will test these methods in the test class.

Notes:

1. You need to understand how class Scoreboard is defined and implemented and pay particular attention to the implementation of methods remove (int) and add(GameEntry)!

2. Do not use Java API defined data structures such as Collections.reverse(), . CODE:

public class Scoreboard { private int numEntries = 0; // number of actual entries private GameEntry[] board; // array of game entries (names & scores) /** Constructs an empty scoreboard with the given capacity for storing entries. */ public Scoreboard(int capacity) { board = new GameEntry[capacity]; }

/** Attempt to add a new score to the collection (if it is high enough) */ public void add(GameEntry e) { int newScore = e.getScore(); // is the new entry e really a high score? if (numEntries < board.length || newScore > board[numEntries-1].getScore()) { if (numEntries < board.length) // no score drops from the board numEntries++; // so overall number increases // shift any lower scores rightward to make room for the new entry int j = numEntries - 1; while (j > 0 && board[j-1].getScore() < newScore) { board[j] = board[j-1]; // shift entry from j-1 to j j--; // and decrement j } board[j] = e; // when done, add new entry } }

/** Remove and return the high score at index i. */ public GameEntry remove(int i) throws IndexOutOfBoundsException { if (i < 0 || i >= numEntries) throw new IndexOutOfBoundsException("Invalid index: " + i); GameEntry temp = board[i]; // save the object to be removed for (int j = i; j < numEntries - 1; j++) // count up from i (not down) board[j] = board[j+1]; // move one cell to the left board[numEntries -1 ] = null; // null out the old last score numEntries--; return temp; // return the removed object }

/** Returns a string representation of the high scores list. */ public String toString() { StringBuilder sb = new StringBuilder("["); for (int j = 0; j < numEntries; j++) { if (j > 0) sb.append(", "); // separate entries by commas sb.append(board[j]); } sb.append("]"); return sb.toString(); }

}

public class GameEntry { private String name; // name of the person earning this score private int score; // the score value /** Constructs a game entry with given parameters.. */ public GameEntry(String n, int s) { name = n; score = s; } /** Returns the name field. */ public String getName() { return name; } /** Returns the score field. */ public int getScore() { return score; } /** Returns a string representation of this entry. */ public String toString() { return "(" + name + ", " + score + ")"; } }

import java.util.Scanner;

/** Class for storing high scores in an array in nondecreasing order. */ public class ScoreboardTest{ public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.printf("How many highest scores on the scoreboard? "); int N = input.nextInt(); Scoreboard highscores = new Scoreboard(N); String[] names = {"Rob", "Rose", "Jill", "Jack", "Anna", "Paul", "Bob", "John", "Dianna"}; int[] scores = {750, 590, 740, 510, 660, 720, 400, 660, 750};

for (int i=0; i < names.length; i++) { GameEntry gE = new GameEntry(names[i], scores[i]); System.out.println("Adding " + gE); highscores.add(gE); System.out.println(" Scoreboard: " + highscores); } System.out.println("Removing score at index " + 3); highscores.remove(3); System.out.println(highscores); System.out.println("Removing score at index " + 0); highscores.remove(0); System.out.println(highscores); System.out.println("Removing score at index " + 1); highscores.remove(1); System.out.println(highscores); System.out.println("Removing score at index " + 1); highscores.remove(1); System.out.println(highscores); System.out.println("Removing score at index " + 0); highscores.remove(0); System.out.println(highscores); } }