def swap_values(self, value_1, value_2):
if self.is_empty():
raise EmptyCollection()
if value_1 != value_2:
# TODO: this code can be improved to find value_1 and value_2 in one iteration
previous_value_1, current_value_1 = self._get_nodes_based_on_value(
value=value_1,
head=self._head,
)
previous_value_2, current_value_2 = self._get_nodes_based_on_value(
value=value_2,
head=self._head,
)
if previous_value_1 is None:
self._head = current_value_2
else:
previous_value_1.next_node = current_value_2
if previous_value_2 is None:
self._head = current_value_1
else:
previous_value_2.next_node = current_value_1
tmp_next_node_for_value_2 = current_value_2.next_node
current_value_2.next_node = current_value_1.next_node
current_value_1.next_node = tmp_next_node_for_value_2
if current_value_1.next_node is None:
self._tail = current_value_1
if current_value_2.next_node is None:
self._tail = current_value_2
def dequeue(self):
if self.is_empty():
raise EmptyCollection('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 get_last_operation(self) -> Any:
if self.is_empty():
raise EmptyCollection('Collection is empty')
self._decrease_next_operation_index()
last_operation = self._operations[self._index_of_next_operation]
self._operations[self._index_of_next_operation] = None
self._size -= 1
return last_operation
def dequeue(self):
if self.is_empty():
raise EmptyCollection('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 get_first_and_remove(self):
if self.is_empty():
raise EmptyCollection()
value = self.first
if len(self) == 1:
self._head = None
self._tail = None
else:
self._head = self._head.next_node
self._size -= 1
return value
def first(self):
if self.is_empty():
raise EmptyCollection('Queue is empty')
return self._data[self._front]
def raise_exception_if_empty(self):
if self.is_empty():
raise EmptyCollection('This collection is empty')
def first(self) -> Any:
if self.is_empty():
raise EmptyCollection('No values to get!')
return self._head.value
def first(self):
if self.is_empty():
raise EmptyCollection('Queue is empty')
head = self._tail._next
return head._element
def _raise_if_empty(self):
if self.is_empty():
raise EmptyCollection()