113 lines
2.6 KiB
Python
113 lines
2.6 KiB
Python
|
class Node(object):
|
||
|
|
|
||
|
|
def __init__ (self, d, n = None, p = None):
|
||
|
|
self.data = d
|
||
|
|
self.next_node = n
|
||
|
|
self.prev_node = p
|
||
|
|
|
||
|
|
def get_next (self):
|
||
|
|
return self.next_node
|
||
|
|
|
||
|
|
def set_next (self, n):
|
||
|
|
self.next_node = n
|
||
|
|
|
||
|
|
def get_prev (self):
|
||
|
|
return self.prev_node
|
||
|
|
|
||
|
|
def set_prev (self, p):
|
||
|
|
self.prev_node = p
|
||
|
|
|
||
|
|
def get_data (self):
|
||
|
|
return self.data
|
||
|
|
|
||
|
|
def set_data (self, d):
|
||
|
|
self.data = d
|
||
|
|
|
||
|
|
def to_string (self):
|
||
|
|
return "Node value: " + str(self.data)
|
||
|
|
|
||
|
|
def has_next (self):
|
||
|
|
if self.get_next() is None:
|
||
|
|
return False
|
||
|
|
return True
|
||
|
|
|
||
|
|
class DoublyLinkedList (object):
|
||
|
|
|
||
|
|
def __init__ (self, r = None):
|
||
|
|
self.root = r
|
||
|
|
self.last = r
|
||
|
|
self.size = 0
|
||
|
|
|
||
|
|
def get_size (self):
|
||
|
|
return self.size
|
||
|
|
|
||
|
|
def add (self, d):
|
||
|
|
if self.size == 0:
|
||
|
|
self.root = Node(d)
|
||
|
|
self.last = self.root
|
||
|
|
else:
|
||
|
|
new_node = Node(d, self.root)
|
||
|
|
self.root.set_prev(new_node)
|
||
|
|
self.root = new_node
|
||
|
|
self.size += 1
|
||
|
|
|
||
|
|
def remove (self, d):
|
||
|
|
this_node = self.root
|
||
|
|
while this_node is not None:
|
||
|
|
if this_node.get_data() == d:
|
||
|
|
if this_node.get_prev() is not None:
|
||
|
|
if this_node.has_next(): # delete a middle node
|
||
|
|
this_node.get_prev().set_next(this_node.get_next())
|
||
|
|
this_node.get_next().set_prev(this_node.get_prev())
|
||
|
|
else: # delete last node
|
||
|
|
this_node.get_prev().set_next(None)
|
||
|
|
self.last = this_node.get_prev()
|
||
|
|
else: # delete root node
|
||
|
|
self.root = this_node.get_next()
|
||
|
|
this_node.get_next().set_prev(self.root)
|
||
|
|
self.size -= 1
|
||
|
|
return True # data removed
|
||
|
|
else:
|
||
|
|
this_node = this_node.get_next()
|
||
|
|
return False # data not found
|
||
|
|
|
||
|
|
def find (self, d):
|
||
|
|
this_node = self.root
|
||
|
|
while this_node is not None:
|
||
|
|
if this_node.get_data() == d:
|
||
|
|
return d
|
||
|
|
elif this_node.get_next() == self.root:
|
||
|
|
return False
|
||
|
|
else:
|
||
|
|
this_node = this_node.get_next()
|
||
|
|
|
||
|
|
def print_list (self):
|
||
|
|
print ("Print List..........")
|
||
|
|
if self.root is None:
|
||
|
|
return
|
||
|
|
this_node = self.root
|
||
|
|
print (this_node.to_string())
|
||
|
|
while this_node.has_next():
|
||
|
|
this_node = this_node.get_next()
|
||
|
|
print (this_node.to_string())
|
||
|
|
|
||
|
|
def main():
|
||
|
|
myList = DoublyLinkedList()
|
||
|
|
myList.add(5)
|
||
|
|
myList.add(9)
|
||
|
|
myList.add(3)
|
||
|
|
myList.add(8)
|
||
|
|
myList.add(9)
|
||
|
|
print("size="+str(myList.get_size()))
|
||
|
|
myList.print_list()
|
||
|
|
myList.remove(8)
|
||
|
|
print("size="+str(myList.get_size()))
|
||
|
|
print("Remove 15", myList.remove(15))
|
||
|
|
myList.add(21)
|
||
|
|
myList.add(22)
|
||
|
|
myList.remove(5)
|
||
|
|
myList.print_list()
|
||
|
|
print("size="+str(myList.get_size()))
|
||
|
|
print(myList.last.get_prev().to_string())
|
||
|
|
|
||
|
|
main()
|