Question

Package pacman.score

Class ScoreBoard

• Object
• • ScoreBoard

• public class ScoreBoard
  extends Object

  ScoreBoard contains previous scores and the current score of the PacmanGame. A score is a name and value that a valid name only contains the following characters:
  • A to Z
  • a to z
  • 0 to 9
  and must have a length greater than 0. The value is a integer that is equal to or greater than 0.

  Implement this for Assignment 1

• • Constructor Summary

    Constructors

    Constructor	Description
    ScoreBoard()	Creates a score board that has no entries and a current score of 0.

  • Method Summary

    All MethodsInstance MethodsConcrete Methods

    Modifier and Type	Method	Description
    List<String>	getEntriesByName()	Gets the stored entries ordered by Name in lexicographic order.
    List<String>	getEntriesByScore()	Gets the stored entries ordered by the score in descending order ( 9999 first then 9998 and so on ...) then in lexicographic order of the name if the scores match.
    int	getScore()	Get the current score.
    void	increaseScore​(int additional)	Increases the score if the given additional is greater than 0.
    void	reset()	Set the current score to 0.
    void	setScore​(String name, int score)	Sets the score for the given name if: name is not null name is a valid score name score is equal to or greater than zero. This should override any score stored for the given name if name and score are valid.
    void	setScores​(Map<String,​Integer> scores)	Sets a collection of scores if "scores" is not null, otherwise no scores are modified.

    • Methods inherited from class Object

      clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

• • Constructor Detail

    • ScoreBoard

      public ScoreBoard()

      Creates a score board that has no entries and a current score of 0.

      Implement this for Assignment 1

  • Method Detail

    • getEntriesByName

      public List<String> getEntriesByName()

      Gets the stored entries ordered by Name in lexicographic order. The format of the list should be:
      1. Score name with a single space afterwards
      2. A single colon
      3. A space then the value of the score with no leading zeros.
      Example:

           ScoreBoard board = new ScoreBoard();
           board.setScore("Fred", 100);
           board.setScore("fred", 20);
           board.setScore("Fred", 24);
      
           List<String> scores = board.getEntriesByName();
           System.out.println(scores);
      
           // this outputs:
           // [Fred : 24, fred : 20]
      
       

      Returns:

      List of scores formatted as "NAME : VALUE" in the order described above or an empty list if no entries are stored.

      Implement this for Assignment 1

    • getEntriesByScore

      public List<String> getEntriesByScore()

      Gets the stored entries ordered by the score in descending order ( 9999 first then 9998 and so on ...) then in lexicographic order of the name if the scores match. The format of the list should be:
      1. Score name with a single space afterwards
      2. A single colon
      3. A space then the value of the score with no leading zeros.
      Example:

           ScoreBoard board = new ScoreBoard();
           board.setScore("Alfie", 100);
           board.setScore("richard", 20);
           board.setScore("Alfie", 24);
           board.setScore("ben", 20);
      
           List<String> scores = board.getEntriesByScore();
           System.out.println(scores);
      
           // this outputs
           // [Alfie : 24, ben : 20, richard : 20]
       

      Returns:

      List of scores formatted as "NAME : VALUE" in the order described above or an empty list if no entries are stored.

      Implement this for Assignment 1

    • setScore

      public void setScore​(String name, int score)

      Sets the score for the given name if:
      • name is not null
      • name is a valid score name
      • score is equal to or greater than zero.
      This should override any score stored for the given name if name and score are valid.

      Parameters:

      name - of scorer.

      score - to set to the given name.

      Implement this for Assignment 1

    • setScores

      public void setScores​(Map<String,​Integer> scores)

      Sets a collection of scores if "scores" is not null, otherwise no scores are modified. For each score contained in the scores if:
      • name is not null
      • name is a valid score name
      • score is equal to or greater than zero.
      the score will be set and override any stored score for the given name, otherwise it will be skipped.

      Parameters:

      scores - to add.

      Implement this for Assignment 1

    • increaseScore

      public void increaseScore​(int additional)

      Increases the score if the given additional is greater than 0. No change to the current score if additional is less than or equal to 0.

      Parameters:

      additional - score to add.

      Implement this for Assignment 1

    • getScore

      public int getScore()

      Get the current score.

      Returns:

      the current score.

      Implement this for Assignment 1

    • reset

      public void reset()

      Set the current score to 0.

How to use treemap to solve this problem?

Answer 1

package packman.score;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Map.Entry.*;
import java.util.stream.Collectors;

public class ScoreBoard extends Object {

   HashMap<String, Integer> scoreboard = new HashMap<String, Integer>();

   int currentScore;

   public ScoreBoard() {

       this.currentScore = 0;

   }

   public List<String> getEntriesByName() {

       List<String> names = new ArrayList<String>(scoreboard.keySet());
       Collections.sort(names);

       List<String> result = new ArrayList<>();

       for (String str : names) {
           result.add(str + " : " + scoreboard.get(str));
       }
       return result;

   }

   public List<String> getEntriesByScore() {
      
      
       //Using java8 feature
       HashMap<String, Integer> sortedMap =scoreboard
           .entrySet()
           .stream()
           .sorted(Map.Entry.comparingByValue())
           .collect(
                   Collectors.toMap(e -> e.getKey(), e -> e.getValue(), (e1, e2) -> e2,LinkedHashMap::new));
         
       Iterator<Entry<String, Integer>> iterator = sortedMap.entrySet().iterator();
       List<String> result = new ArrayList<>();
           // Iterate over the HashMap
           while (iterator.hasNext()) {

               // Get the entry at this iteration
               Entry<String, Integer> entry = iterator.next();
              
               result.add(entry.getKey()+" : "+entry.getValue());
              
           }

       return result;

   }

   public int getScore() {
       return this.currentScore;

   }

   public void increaseScore(int additional) {

       if (additional > 0)
           this.currentScore = this.currentScore + additional;
   }

   public void reset() {

       this.currentScore = 0;
   }

   public void setScores(HashMap<String, Integer> scores) {

       Iterator<Entry<String, Integer>> iterator = scores.entrySet().iterator();

       // Iterate over the HashMap
       while (iterator.hasNext()) {

           // Get the entry at this iteration
           Entry<String, Integer> entry = iterator.next();

           boolean flag = entry.getKey().matches("[A-Za-z0-9]{1,}");

           if (flag) {

               if (entry.getValue() >= 0) {

                   scoreboard.put(entry.getKey(), entry.getValue());

               }

               else
                   System.out.println("Invalid score");
           }

           else
               System.out.println("Invalid Name");
       }

   }

   public void setScore(String name, int score) {

       boolean flag = name.matches("[A-Za-z0-9]{1,}");

       if (flag) {

           if (score >= 0) {

               scoreboard.put(name, score);

           }

           else
               System.out.println("Invalid score");
       }

       else
           System.out.println("Invalid Name");
   }

}

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