COSC 1030 Introduction to Computer Science II Assignment 3: Tournaments (Due: March 26 at Noon)

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1 Main Points COSC 1030 Introduction to Computer Science II Assignment 3: Tournaments (ue: March 26 at Noon) Learning objectives Review Java programming with arrays and singly linked lists Review classes and objects Specification of exception handling ocumentation Testing Assignment Overview Congratulations! You have been hired by the Tournament Scheduling Committee (TSC) to develop and test several Java classes used for scheduling matches in a tournament. The TSC is interested in scheduling matches between a number of players. ach match is played between two players. Matches are scheduled in a number of rounds and on several courts. No two matches in the same round will use the same court. The following table shows a schedule for a round robin tournament with 8 players, 7 rounds, and 7 courts. The players are denoted by letters A-H. In Round 0 the following matches are scheduled: A plays against B in Court 0 C plays against G in Court 3 plays against H in Court 5, and plays against in Court 6 Court 3 Court 4 Court 5 Court 6 Round 0 A,B C,G,H, Round 1, A,C,H G,B Round 2 H,C,G A,,B Round 3 B, G,H A,,C Round 4 G, C, H,B A, Round 5 H,, B,C A, G Round 6 B,,G C, A, H This schedule has number of nice properties, including a) very player plays against every other player exactly once during the tournament, b) very player plays exactly once in every round, and c) very player plays exactly once in each court. Not all tournaments can be scheduled having such nice properties. In this assignment we will not be concerned with how to schedule balanced tournaments. The TSC has asked you to develop a Java class, called Tournament, which could be used to maintain a tournament. The TSC has also mentioned the possibility that some courts may not be used at all and that all matches in a given round may be cancelled. Hence it is possible to have an empty rounds and empty courts

2 After consultation with our senior designers, we decided to encapsulate information about each match in a Java class named Match. This class has already been written for you. In order to save memory space, we decided to use singly linked lists for keeping track of matches in each round and for each court. Hence, for each round, a linked list holds the matches for that round. Also for every court a linked list keeps track of the matches played on that court. These two sets of linked lists, however, share all the matches in the schedule as their nodes. Two arrays, representing rounds and courts hold references to the beginning of the list of matches for rounds and courts respectively. Note that you, yourself, are responsible for implementing the linked list using the Match class. Aside from the two arrays provided in the Tournament class, you may NOT use a linked list from the Java library. As an example, the internal organization of the data for the following tournament is depicted here. Court 3 Court 4 Court 5 Court 6 Round 0 Round 1,,H Round 2 A,,B Round 3 Round 4 G, C, A, Round 5 A, G Round 6 B,,G roundlist CourtList A 3 H B 4 G C A 5 A G 6 B G In the above figure a filled bullet at the end of a link represents a null reference

3 ach node of the linked lists, Match, (see table below) contains the name of player1, the name of player2, the round and court numbers, and link references to the next match in round and the next match in court. These references are required to link matches in the same round and in the same court so they can be conveniently found. The following table describes these fields. round an int in the range of 0 to (number of rounds -1) court an int in the range of 0 to (number of courts -1) player1 a string referencing the name of player 1 player2 a string referencing the name of player 2 nextinround a reference to the next match in this round nextincourt a reference to the next match in this court The code for this class is already written for you. Tasks Complete/develop the following methods and calsses InvalidRoundOrCourtxception Create and document the class InvalidRoundOrCourtxception. This class should extend the Runtimexception class. xceptions of this type are thrown if the specified round or court is not valid in the given tournament. No code is provided for this class. The bodies of incomplete methods in the Tournament class The signatures of these methods and a small description are provided. complete the following methods: You need to public void addmatch(match amatch) throws InvalidRoundOrCourtxception, NullPointerxception - This method adds a new match to the tournament using the two methods: addtoround and addtocourt. If a match with the given coordinates (round, court) has already been scheduled, the method simply replaces the name of the old players with the new ones. private Match findmatch(int round, int court) throws InvalidRoundOrCourtxception - Given coordinates (round, court), the method simply returns a reference to the match node in that position. If no match has been scheduled for (round, court), then this method returns null. It throws an exception if one of round/court is invalid. private void addtoround(match amatch, int round, int court) - Add the given match to the linked list for the given round private void addtocourt(match amatch, int round, int court) - Add the given match to the linked list for the given court public Match removematch(int round, int court) throws InvalidRoundOrCourtxception - Remove the match scheduled in "round" and "court". This method uses the two methods: removeromround and removeromcourt, to remove the match from two singly linked lists. private Match removeromround(int r, int c) - Remove the given match from the singly linked list of the given row - 3 -

4 private Match removeromcourt(int r, int c) - Remove the match from the singly linked list of the given court. IMPORTANT: You should NOT modify the following methods in Tournament: tostring getmatchesinround getmatchesincourt You are NOT allowed to modify the class Match. Note that if the sum of the length of the player's name in a match is longer than "WITH -2", defined in tostring method of Tournamnet, then output will not be properly formatted. Grading A total of 5 marks will be allocated for this assignment, as follows: 1 mark for attending the assignment presentation lab in the week of March 8. 1 mark for showing a partial solution to the assignment to your TA (in person) during the week of March 15, either in the tutorial or during your TAs office hour. 2 marks for correctness as evaluated by testing conducted on the files you submit using the submit command (Noon March 26) 1 mark for discussing solutions with your TA during the tutorial in the week of March 29. Testing and ebugging You may use the provided methods for testing and debugging your code. In particular, the methods: getmatchesinround and getmatchesincourt, can be used to examine whether the nodes are inserted correctly within the structure. You should conduct sufficient number of tests to verify that your program works for all possible cases. A simple test harness has been provided. The test program and its output are as follows: import type.lang.io; public class TestTournament{ public static void main(string[] args){ Tournament m = new Tournament(3, 3); m.addmatch(new Match("Kim", "Tom", 0, 0)); m.addmatch(new Match("Kim", "Liz", 2, 2)); m.addmatch(new Match("Tim", "Bob", 1, 2)); m.addmatch(new Match("Bob", "Hop", 2, 0)); m.addmatch(new Match("Sue", "Sam", 2, 0)); m.removematch(0, 0); for(int i = 0; i < 3; i++) IO.println(m.getMatchesInRound(i)); for(int i =0; i < 3; i++) IO.println(m.getMatchesInCourt(i)); m.addmatch(new Match("Ron", "Kate", 0, 4)); } } - 4 -

5 java TestTournament Round 0: -,- -,- -,- Round 2: -,- -,- -,- Round 2: -,- -,- -,- Round 2: -,- -,- Kim,Liz Round 2: -,- -,- Kim,Liz Round 2: Bob,Hop -,- Kim,Liz Round 2: Sue,Sam -,- Kim,Liz Round 0: -,- -,- -,- Round 2: Sue,Sam -,- Kim,Liz Round 0: Round 1: -> Tim,Bob (1, 2) Round 2: -> Sue,Sam (2, 0) -> Kim,Liz (2, 2) Court 0: -> Sue,Sam (2, 0) Court 1: Court 2: -> Tim,Bob (1, 2) -> Kim,Liz (2, 2) InvalidRoundOrCourtxception: Invald round or court. at Tournament.findMatch(Tournament.java:65) at Tournament.addMatch(Tournament.java:38) at TestTournament.main(TestTournament.java:25) "java TestTournament" completed. > - 5 -