def dequeue(self): #deletes the last elemet in the fill
#complexity O(n) if empty is empty else complexity O(1)
if self.__empty.emptyList():
if self.__fill.emptyList():
raise Exception("Queue is Empty")
self.__empty = self.__fill.reverse(Nil()) #takes linear time
self.__fill = Nil()
op = Option()
if self.isEmpty():
op.setOp(False)
else:
op.setEl(self.__empty.getEl(0))
self.__empty.deletFirst()
return op #returns the value
class IL_Stack(Stack): #stack with immutable list
def __init__(self):
self.__elements = Nil() #immutable list but stack class mutable
self.__iter = Imm_L_I()
def push(self, el): #adds new element in to the list
#complexity O(1)
newS = Cons(el, self.__elements)
self.__elements = newS
self.__iter.copy(self.__elements)
x = Unit()
return x #returns Unit
def top(self): #returns the top element
#complexity O(1)
x = Option()
if self.__elements.emptyList():
x.setOp(False)
else:
x.setEl(self.__elements.getEl(0))
return x #returns empty option if list is empty
def pop(self): #pops the first elment if possile
#complexity O(1)
x = Option()
if self.__elements.emptyList():
raise Exception(
"Stack is Empty") #raises exception if list is empty
else:
x.setEl(self.__elements.getEl(0))
self.__elements.deletFirst(
) #deletes the First element if possible
return x
def iterator(self): #creates iterator for the stack
#complexity O(1)
return self.__iter
def __init__(self):
self.__fill = Nil()
self.__empty = Nil()
class IL_Queue(Queue): #queue with immutable list
def __init__(self):
self.__fill = Nil()
self.__empty = Nil()
## self.__concate = Nil()
## self.__iter = Imm_L_I()
def enqueue(self, el): #adds a new element into the list
#complexity O(1)
newQ = Cons(el, self.__fill)
self.__fill = newQ
x = Unit()
return x #returns Unit object
def dequeue(self): #deletes the last elemet in the fill
#complexity O(n) if empty is empty else complexity O(1)
if self.__empty.emptyList():
if self.__fill.emptyList():
raise Exception("Queue is Empty")
self.__empty = self.__fill.reverse(Nil()) #takes linear time
self.__fill = Nil()
op = Option()
if self.isEmpty():
op.setOp(False)
else:
op.setEl(self.__empty.getEl(0))
self.__empty.deletFirst()
return op #returns the value
def isEmpty(self): #checks the queue is empty or not
#complexity O(1)
return self.__fill.emptyList() and self.__empty.emptyList()
def print(self): #prints the list
#complexity O(n)
print("printing fill")
self.__fill.print()
print("printing empty")
self.__empty.print()
def __init__(self):
self.__elements = Nil() #immutable list but stack class mutable
self.__iter = Imm_L_I()
def __init__(self):
#complexity O(1)
self.__elements = Nil()
self.__iter = Imm_L_I() #iterator object for the listset