Answer:
#Implementation of Queue class
class Queue
#Implementation of _init_
def _init_(self, limit=10):
#calculate the self.data
self.data = [None] * limit
self.head = -1
self.tail = -1
#Implementation of enqueue function
def enqueue(self, val):
#check self.head - self.tail is equal to 1
if self.head - self.tail == 1:
raise NotImplementedError
#check len(self.data) - 1 is equal to elf.tail
if len(self.data) - 1 == self.tail and self.head == 0:
raise NotImplementedError
#check self.head is equal to -1
if self.head == -1 and self.tail == -1:
self.data[0] = val
self.head = 0
self.tail = 0
else:
#check len(self.data) - 1 is equal to self.tail
if len(self.data) - 1 == self.tail and self.head != 0:
self.tail = -1
self.data[self.tail + 1] = val
#increment the self.tail value
self.tail = self.tail + 1
#Implementation of dequeue method
def dequeue(self):
#check self.head is equal to self.tail
if self.head == self.tail:
temp = self.head
self.head = -1
self.tail = -1
return self.data[temp]
#check self.head is equal to -1
if self.head == -1 and self.tail == -1:
#raise NotImplementedError
raise NotImplementedError
#check self.head is not equal to len(self.data)
if self.head != len(self.data):
result = self.data[self.head]
self.data[self.head] = None
self.head = self.head + 1
else:
# resetting head value
self.head = 0
result = self.data[self.head]
self.data[self.head] = None
self.head = self.head + 1
return result
#Implementation of resize method
def resize(self, newsize):
#check len(self.data) is less than newsize
assert (len(self.data) < newsize)
newdata = [None] * newsize
head = self.head
current = self.data[head]
countValue = 0
#Iterate the loop
while current != None:
newdata[countValue] = current
countValue += 1
#check countValue is not equal to 0
if countValue != 0 and head == self.tail:
break
#check head is not equal to
#len(self.data) - 1
if head != len(self.data) - 1:
head = head + 1
current = self.data[head]
else:
head = 0
current = self.data[head]
self.data = newdata
self.head = 0
self.tail = countValue - 1
#Implementation of empty method
def empty(self):
#check self.head is equal to -1
# and self.tail is equal to -1
if self.head == -1 and self.tail == -1:
return True
return False
#Implementation of _bool_() method
def _bool_(self):
return not self.empty()
#Implementation of _str_() method
def _str_(self):
if not (self):
return ''
return ', '.join(str(x) for x in self)
#Implementation of _repr_ method
def _repr_(self):
return str(self)
#Implementation of _iter_ method
def _iter_(self):
head = self.head
current = self.data[head]
countValue = 0
#Iterate the loop
while current != None:
yield current
countValue += 1
#check countValue is not equal to zero
#check head is equal to self.tail
if countValue != 0 and head == self.tail:
break
#check head is not equal to len(self.data) - 1
if head != len(self.data) - 1:
head = head + 1
current = self.data[head]
else:
head = 0
current = self.data[head
Explanation:-
Output:
