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 delete(self, el):
#complexity O(1)
x = Option()
if self.contains(el):
x.setEl(el)
self.__vector[el] = False
return x
print("Element is not in the set", el)
return x
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 delete(self, n):
#complexity O(n)
x = Option()
while self.__iter.hasNext():
if n is self.__iter.iter.getHead():
self.__iter.iter.deletFirst(
) #delets the element from the list
self.__iter.init()
x.setEl(n)
return x
self.__iter.Next()
print("Element is not in the set", n)
return x
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
