Exercises
Queues

  1. What is a queue (at the logical level)?

  2. Give an example of a queue in everyday life.

  3. Use the header file to see how the seven ListQueue member functions compare with the seven apstack member functions in the table.
    apstackListQueue
    push(n) 
    pop(n) 
    isEmpty( ) 
    pop( ) 
    n = top( ) 
    n = length( ) 
    makeEmpty( ) 

  4. In problems 4 - 6, display each program fragment's output. Show your work.

    ListQueue Q;
    Q.enqueue(5);
    Q.enqueue(6);
    Q.enqueue(7);
    Q.enqueue(8);
    int x=Q.peekFront( );
    int y;
    y=Q.dequeue();
    Q.enqueue(x);
    Q.enqueue(++y);
    Q.dequeue();
    y=Q.dequeue();
    while( !Q.isEmpty( ) )
       x=Q.dequeue();
    System.out.println(x);

  5. ListQueue Q;
    int x = 2;
    Q.enqueue(4);
    Q.enqueue(x);
    Q.enqueue(Q.peekFront( ));
    Q.enqueue(3+Q.peekFront( ));
    Q.enqueue(0);
    Q.dequeue();
    while(!Q.isEmpty())
    {
       x=Q.dequeue();
       System.out.print(x);}
    System.out.println();

  6. apstack S;
    ListQueue Q;
    int a=0, b=1;
    int c=a+b;
    while (c<10)
    {
       if (c%2==0)
          S.push(c);
       else Q.enqueue(c);
       a=b;
       b=c;
       c=a+b;
    }
    while ( !S.isEmpty( ) )
    {    S.pop(c);
       System.out.print(c);
    }
    while ( !Q.isEmpty( ) )
    {    c=Q.dequeue();
       System.out.print(c);
    }

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