Compound Data Structures
The SET - Solutions

The following represent strategies/algorithms and NOT actual coded solutions - it is thought there is definite advantage here for students to actually wrestle with the actual code to get a working solution. There may be MANY different ways to encode these solutions - get creative and try to be efficient

1

1. Procedure PrintSet(theSet:byteset);
   var loop : byte;
   begin
   ...for loop := 1 to 255 do
   ......if loop in theSet
   .........then write(loop,', ')
   end; {PrintSet}
   
   
2. Procedure AddElement(var theSet:byteset; element : byte);
   begin
   ...theset := theset+ [element]
   end; {AddElement}
   
   
3. Function Cardinality(theset:byteset):byte;
   var counter, loop : byte;
   begin
   ...counter := 0;
   ...for loop := 0 to 255 do
   ......if loop in theset
   .........then inc(counter);
   ...Cardinality := counter;
   end; {Cardinality}
   
   
4. Procedure RemoveElement(var theSet:byteset; element : byte);
   begin
   ...theset := theset- [element]
   end; {AddElement}
   
   
5. Procedure CreateRandomSet (var theset:byteset; num : byte);
   var thing, counter : byte;
   begin
   ...randomize;
   ...counter := 0;
   ...repeat
   ......thing := random(256);
   ......if not(thing in theset)
   .........then
   ............begin
   ...............theset := theset + [thing];
   ...............inc(counter)
   ............end
   ...until counter = num
   end; {dreate random set}

2. This program requires a simple set structure used over aand over using a loop. Each game, you clear the set, randomly insert a number of numbers into it (see 1(e) above) and then output the set before clearing it and starting again

3

1. EnglishDays, MathematicsDays, ComputerDays, BiologyDays: Daysets
   
   
2. EnglishDays := [mon, tue, thu]; and so on
   
   
3. write(mon in EnglishDays)
   write((wed in BiologyDays) and (thu in BiologyDays))