Question

Problem 3 (20 points) Implement a queue abstract data type using the UnorderedList class.

Answer 1

class Queue:
    def __init__(self): # initializing
        self.items = []
        self.size = 0

    def is_empty(self): #check list is empty
        return self.items == []

    def enqueue(self, data): #enqueue value
        self.items.append(data)
        self.size += 1
    def dequeue(self): #dequeue value
        self.size -= 1
        return self.items.pop(0)

    def size(self): #return size
        return self.size

def main():

    q = Queue() #creating object
    while True: #run while 4 is not input
        print('1 enqueue ')
        print('2 dequeue')
        print('3 size')
        print('4 quit')
        do = int(input('What would you like to do? '))

        if do == 1:
            val = int(input("Enter value: "))
            q.enqueue(val)
        elif do == 2:
            if q.is_empty():
                print('Queue is empty.')
            else:
                print('Dequeued value: ', q.dequeue())
        elif do == 3:
            print('size: ', q.size)

        elif do == 4:
            break;


if __name__ == '__main__':main() #main function