Post Lab 20

Tracing Queues

Draw the state of the queue at the end of each of these blocks of code.

1.       my_queue = Queue()
   
         for i in range(5):
             my_queue.enqueue(i)
   
         my_queue.dequeue()
         my_queue.dequeue()
       

2.       my_queue = Queue()
   
         for i in range(5):
             my_queue.enqueue(i)
   
         my_queue.dequeue()
   
         for i in range(5, 10):
             my_queue.enqueue(i)
   
         my_queue.dequeue()
         my_queue.dequeue()
         my_queue.dequeue()
       

3.       my_queue = Queue()
   
         for i in range(10):
             if i % 2 == 0:
                 my_queue.enqueue(i)
             else:
                 my_queue.dequeue()
       

4.       my_queue = Queue()
   
         for i in range(10):
             if i % 2 == 0:
                 my_queue.enqueue(i)
             else:
                 removed_value = my_queue.dequeue()
                 my_queue.enqueue(removed_value)
   
       

5.       my_queue = Queue()
   
         for i in range(10):
             if i % 2 == 0:
                 my_queue.enqueue(i)
             elif i % 3 == 0:
                 my_queue.dequeue()
             else:
                 removed_value = my_queue.dequeue()
                 my_queue.enqueue(removed_value)
       

6.       my_queue = Queue()
   
         for i in range(10):
             my_queue.enqueue(i)
   
         while my_queue.peek() != 5:
             my_queue.enqueue(my_queue.dequeue())
   
       

7.       my_queue = Queue()
   
         for i in range(10):
             my_queue.enqueue(i)
   
         while my_queue.peek() != 5:
             if my_queue.peek() % 2 == 0:
                 my_queue.enqueue(my_queue.dequeue())
             else:
                 my_queue.dequeue()
   
       

8.       my_queue = Queue()
         temp_list = []
         for i in range(10):
             my_queue.enqueue(i)
   
         for j in range(5):
             temp_list.append(my_queue.dequeue())
   
         for item in temp_list:
             my_queue.enqueue(item)
       

Submission

Bring this completed worksheet with you to the beginning of class on Wednesday.