class Queue(object):
"""
FIFO queue based on single linked list
All operations are O(1)
"""
def __init__(self, data=None):
# Use composition to hide the linked list implementation details
self._linked_list = LinkedList(
) if not data else LinkedList.from_array(data)
self._lock = Lock()
def __iter__(self):
yield from self._linked_list
def __len__(self):
with self._lock:
return len(self._linked_list)
def enqueue(self, value):
with self._lock:
self._linked_list.append(value)
def dequeue(self):
with self._lock:
return self._linked_list.remove(0).value
def peek(self):
with self._lock:
return self._linked_list.get(0).value
def is_empty(self):
with self._lock:
return len(self._linked_list) == 0
class Queue(object):
"""
FIFO queue based on single linked list
All operations are O(1)
"""
def __init__(self, data=None):
# Use composition to hide the linked list implementation details
self._linked_list = LinkedList() if not data else LinkedList.from_array(data)
self._lock = Lock()
def __iter__(self):
yield from self._linked_list
def __len__(self):
with self._lock:
return len(self._linked_list)
def enqueue(self, value):
with self._lock:
self._linked_list.append(value)
def dequeue(self):
with self._lock:
return self._linked_list.remove(0).value
def peek(self):
with self._lock:
return self._linked_list.get(0).value
def is_empty(self):
with self._lock:
return len(self._linked_list) == 0
class Stack(object):
"""
FILO queue based on single linked list
All operations are O(1)
"""
def __init__(self):
# Use composition to hide the linked list implementation details
self._linked_list = LinkedList()
self._lock = Lock()
def __len__(self):
with self._lock:
return len(self._linked_list)
def __contains__(self, item):
return item in self._linked_list
def to_array(self):
return list(self._linked_list)[::-1]
def push(self, value):
with self._lock:
self._linked_list.prepend(value)
def pop(self):
with self._lock:
return self._linked_list.remove(0).value
def peek(self, depth=0):
with self._lock:
return self._linked_list.get(depth).value
def is_empty(self):
with self._lock:
return len(self._linked_list) == 0
def size(self):
return len(self._linked_list)
