Chap10Q4.py

def enqueue(queue,x):
    queue.append(x)

def dequeue(queue):
    global front  #using global variable to modify front
    t=queue[front]
    front +=1   #Front is incremented, thus there is no shifting
    return t

l=[]
front =0
enqueue(l,1)# l=[1]
print(l)
enqueue(l,2)# l=[1,2]
print(l)
enqueue(l,3)# l=[1,2,3]
print(l)
print(dequeue(l))# 1 deleted
print(dequeue(l))# 2 deleted