CS 1723 -- A Simple List of Numbers

CS 1723 -- Extended Example
A Simple List of Numbers, with Completed Code

Extended Example -- A List of Numbers With Completed Code:

// ListMain: make use of the List class
public class ListMain { 

   public static void main(String[] args) {
      List list1 = new List();
      GetNext getNext = new GetNext();
      int license;
      while(true) {
         license = getNext.getNextInt();
         if (list1.contains(license))
            System.out.println("TOW  " + license);
         else {
            System.out.println("WARN " + license);
            if (!list1.add(license))
               System.out.println("*** no room for " + license);
         }
         list1.dump();
      }
   }

} 
% java ListMain
123456
WARN 123456
Dump of List, Current size: 1, Maximum size: 6, Empty? false, Full? false
 123456  End of Dump

987654
WARN 987654
Dump of List, Current size: 2, Maximum size: 6, Empty? false, Full? false
 123456 987654  End of Dump

333333
WARN 333333
Dump of List, Current size: 3, Maximum size: 6, Empty? false, Full? false
 123456 987654 333333  End of Dump

987654
TOW  987654
Dump of List, Current size: 3, Maximum size: 6, Empty? false, Full? false
 123456 987654 333333  End of Dump

444444
WARN 444444
Dump of List, Current size: 4, Maximum size: 6, Empty? false, Full? false
 123456 987654 333333 444444  End of Dump

333333
TOW  333333
Dump of List, Current size: 4, Maximum size: 6, Empty? false, Full? false
 123456 987654 333333 444444  End of Dump

555555
WARN 555555
Dump of List, Current size: 5, Maximum size: 6, Empty? false, Full? false
 123456 987654 333333 444444 555555  End of Dump

666666
WARN 666666
Dump of List, Current size: 6, Maximum size: 6, Empty? false, Full? true
 123456 987654 333333 444444 555555 666666  End of Dump

444444
TOW  444444
Dump of List, Current size: 6, Maximum size: 6, Empty? false, Full? true
 123456 987654 333333 444444 555555 666666  End of Dump

777777
WARN 777777
*** no room for 777777
Dump of List, Current size: 6, Maximum size: 6, Empty? false, Full? true
 123456 987654 333333 444444 555555 666666  End of Dump

^C (ctrl-C to terminate)
%

Here are the two other classes (with completed code in boldface):

// List: a simple list of numbers
public class List { 
   // fields 
   private int[] listArray; // the actual list
   private int currentSize; // current number of elements
   private final int INITIAL_SIZE = 6; // initial maximum size
  
   // List: constructor  
   public List () {  
      currentSize = 0; // not needed (already done)
      listArray = new int[INITIAL_SIZE]; // allocate array
   }

   // isEmpty: is the list empty? (initially true)
   public boolean isEmpty() {
      return size() == 0;
   }

   // isFull: is the list full? (initially false)
   public boolean isFull() {
      return size() == listArray.length;
   }

   // add: add x to the list.  No check for duplicates
   public boolean add(int x) {
      if (currentSize < listArray.length) {
         listArray[currentSize++] = x;
         return true;
      }
      return false;
   }

   // contains: is x in the list?
   public boolean contains(int x) {
      for (int i = 0; i < currentSize; i++)
         if (listArray[i] == x) return true;
      return false;
   }

   // size: return number of elements in the list
   public int size() {
      return currentSize;
   }

   // dump: print data for debugging
   public void dump() {
      System.out.println("Dump of List, Current size: " + size() +
         ", Maximum size: " + listArray.length +
         ", Empty? " + isEmpty() +
         ", Full? " + isFull());
      for (int i = 0; i < currentSize; i++)
         System.out.print(" " + listArray[i]);
      System.out.println("  End of Dump\n");
   }
} 
// GetNext: fetch next char or unsigned integer
import java.io.*;
public class GetNext { 
   private Reader in; // internal file name for input stream
  
   // GetNext: constructor  
   public GetNext () { 
      in = new InputStreamReader(System.in);
   }

   // getNextChar: fetches next char
   private char getNextChar() {
      char ch = ' '; // = ' ' to keep compiler happy
      try {
         ch = (char)in.read();
      } catch (IOException e) {
         System.out.println("Exception reading character");
      }
      return ch;
   }

   // getNextInt: fetch unsigned int
   public int getNextInt() {
      String s ;
      char ch = getNextChar();
      while (ch == ' ' || ch == '\n')
         ch = getNextChar();
      s = "" + ch;
      while (Character.isDigit(ch = getNextChar()))
         s += ch;
      return Integer.parseInt(s);
   }
}

CS 1723 -- Extended Example A Simple List of Numbers, with Completed Code

CS 1723 -- Extended Example
A Simple List of Numbers, with Completed Code