Promotional Message Examples

# In this sort of circular Queue, we can insert any number of elements until queue becomes full regardless of empty spaces in the front of the queue
 
class CircularQueue:
 def __init__(self,size):
 self.size = size
 self.head = -1
 self.tail = -1
 self.array = [None] * size
 
 def isEmpty(self):
 if (self.head == -1 & self.tail == -1):
 print(True)
 else:
 print(False)
 
 def peek(self):
 if (self.head == -1 & self.tail == -1):
 print('Queue is empty')
 return None
 else:
 print('First data in queue is : ' + str(self.array[self.head]))
 return self.array[self.head]
 
 
 def add(self, data):
 if ((self.tail+1) % self.size == self.head):
 print('Queue is full')
 return
 if (self.head == -1 & self.tail == -1):
 self.head = 0
 self.tail = (self.tail+1)%self.size
 self.array[self.tail] = data
 print(str(data) + ' was inserted')
 
 def remove(self):
 if (self.head == -1 & self.tail == -1):
 print('Queue is empty')
 elif (self.head == self.tail ):
 self.head=self.tail= -1 
 else:
 print(str(self.array[self.head]) + ' was deleted')
 self.array[self.head] = None 
 self.head = (self.head+1)%self.size
 
 def display(self):
 if (self.head == -1 & self.tail == -1):
 print('Queue is empty')
 else:
 print('Queue is : ' + str(self.array))