def pop(self):
if self.is_empty():
raise EmptyError('Stack is empty')
answer = self._head._element
self._head = self._head._next
self._size -= 1
return answer
def remove_min(self):
if self.is_empty():
raise EmptyError('Priority queue is empty.')
self._swap(0, len(self._data)-1)
item = self._data.pop()
self._downheap(0)
return (item._key, item._value)
def dequeue(self):
if self.is_empty():
raise EmptyError('Queue is empty')
answer = self._data[self._front]
self._data[self._front] = None
self._front = (self._front + 1) % len(self._data)
self._size -= 1
return answer
def dequeue(self):
if self.is_empty():
raise EmptyError('Queue is empty')
oldhead = self._tail._next
if self._size == 1:
self._tail = None
else:
self._tail._next = oldhead._next
self._size -= 1
return oldhead._element
def _find_min(self):
"""Return Position of item with minimum key."""
if self.is_empty():
raise EmptyError('Priority queue is empty')
small = self._data.first()
walk = self._data.after(small)
while walk is not None:
if walk.element() < small.element():
small = walk
walk = self._data.after(walk)
return small
def remove_min(self):
if self.is_empty():
raise EmptyError('Priority queue us empty')
item = self._data.delete(self._data.first())
return (item._key, item._value)
def min(self):
if self.is_empty():
raise EmptyError('Priority queue is empty')
p = self._data.first()
item = p.element()
return (item._key, item._value)
def min(self):
if self.is_empty():
raise EmptyError('Priority queue is empty.')
item = self._data[0]
return (item._key, item._value)
def pop(self):
if self.is_empty():
raise EmptyError('Stack is empty')
return self._data.pop()
def first(self):
if self.is_empty():
raise EmptyError('Queue is empty')
head = self._tail._next
return head._element
def first(self):
if self.is_empty():
raise EmptyError('Dequeue is empty')
return self._header._next._element
def delete_last(self):
if self.is_empty():
raise EmptyError('Dequeue is empty')
return self._delete_node(self._tailer._prev)
def delete_first(self):
if self.is_empty():
raise EmptyError('Dequeue is empty')
return self._delete_node(self._header._next)
def last(self):
if self.is_empty():
raise EmptyError('Dequeue is empty')
return self._tailer._prev._element
def first(self):
if self.is_empty():
raise EmptyError('Queue is empty')
return self._data[self._front]
def top(self):
if self.is_empty():
raise EmptyError('Stack is empty')
return self._head._element