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psf/black code formatting (#1277)

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This commit is contained in:
William Zhang
2019-10-05 01:14:13 -04:00
committed by Christian Clauss
parent 07f04a2e55
commit 9eac17a408
291 changed files with 6014 additions and 4571 deletions
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144
data_structures/binary_tree/binary_search_tree.py
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@ -1,13 +1,14 @@
'''
"""
A binary search Tree
'''
class Node:
"""
class Node:
def __init__(self, label, parent):
self.label = label
self.left = None
self.right = None
#Added in order to delete a node easier
# Added in order to delete a node easier
self.parent = parent
def getLabel(self):
@ -34,8 +35,8 @@ class Node:
def setParent(self, parent):
self.parent = parent
class BinarySearchTree:
class BinarySearchTree:
def __init__(self):
self.root = None
@ -46,90 +47,90 @@ class BinarySearchTree:
if self.empty():
self.root = new_node
else:
#If Tree is not empty
# If Tree is not empty
curr_node = self.root
#While we don't get to a leaf
# While we don't get to a leaf
while curr_node is not None:
#We keep reference of the parent node
# We keep reference of the parent node
parent_node = curr_node
#If node label is less than current node
# If node label is less than current node
if new_node.getLabel() < curr_node.getLabel():
#We go left
# We go left
curr_node = curr_node.getLeft()
else:
#Else we go right
# Else we go right
curr_node = curr_node.getRight()
#We insert the new node in a leaf
# We insert the new node in a leaf
if new_node.getLabel() < parent_node.getLabel():
parent_node.setLeft(new_node)
else:
parent_node.setRight(new_node)
#Set parent to the new node
# Set parent to the new node
new_node.setParent(parent_node)
def delete(self, label):
if (not self.empty()):
#Look for the node with that label
if not self.empty():
# Look for the node with that label
node = self.getNode(label)
#If the node exists
if(node is not None):
#If it has no children
if(node.getLeft() is None and node.getRight() is None):
# If the node exists
if node is not None:
# If it has no children
if node.getLeft() is None and node.getRight() is None:
self.__reassignNodes(node, None)
node = None
#Has only right children
elif(node.getLeft() is None and node.getRight() is not None):
# Has only right children
elif node.getLeft() is None and node.getRight() is not None:
self.__reassignNodes(node, node.getRight())
#Has only left children
elif(node.getLeft() is not None and node.getRight() is None):
# Has only left children
elif node.getLeft() is not None and node.getRight() is None:
self.__reassignNodes(node, node.getLeft())
#Has two children
# Has two children
else:
#Gets the max value of the left branch
# Gets the max value of the left branch
tmpNode = self.getMax(node.getLeft())
#Deletes the tmpNode
# Deletes the tmpNode
self.delete(tmpNode.getLabel())
#Assigns the value to the node to delete and keesp tree structure
# Assigns the value to the node to delete and keesp tree structure
node.setLabel(tmpNode.getLabel())
def getNode(self, label):
curr_node = None
#If the tree is not empty
if(not self.empty()):
#Get tree root
# If the tree is not empty
if not self.empty():
# Get tree root
curr_node = self.getRoot()
#While we don't find the node we look for
#I am using lazy evaluation here to avoid NoneType Attribute error
# While we don't find the node we look for
# I am using lazy evaluation here to avoid NoneType Attribute error
while curr_node is not None and curr_node.getLabel() is not label:
#If node label is less than current node
# If node label is less than current node
if label < curr_node.getLabel():
#We go left
# We go left
curr_node = curr_node.getLeft()
else:
#Else we go right
# Else we go right
curr_node = curr_node.getRight()
return curr_node
def getMax(self, root = None):
if(root is not None):
def getMax(self, root=None):
if root is not None:
curr_node = root
else:
#We go deep on the right branch
# We go deep on the right branch
curr_node = self.getRoot()
if(not self.empty()):
while(curr_node.getRight() is not None):
if not self.empty():
while curr_node.getRight() is not None:
curr_node = curr_node.getRight()
return curr_node
def getMin(self, root = None):
if(root is not None):
def getMin(self, root=None):
if root is not None:
curr_node = root
else:
#We go deep on the left branch
# We go deep on the left branch
curr_node = self.getRoot()
if(not self.empty()):
if not self.empty():
curr_node = self.getRoot()
while(curr_node.getLeft() is not None):
while curr_node.getLeft() is not None:
curr_node = curr_node.getLeft()
return curr_node
@ -150,34 +151,34 @@ class BinarySearchTree:
return self.root
def __isRightChildren(self, node):
if(node == node.getParent().getRight()):
if node == node.getParent().getRight():
return True
return False
def __reassignNodes(self, node, newChildren):
if(newChildren is not None):
if newChildren is not None:
newChildren.setParent(node.getParent())
if(node.getParent() is not None):
#If it is the Right Children
if(self.__isRightChildren(node)):
if node.getParent() is not None:
# If it is the Right Children
if self.__isRightChildren(node):
node.getParent().setRight(newChildren)
else:
#Else it is the left children
# Else it is the left children
node.getParent().setLeft(newChildren)
#This function traversal the tree. By default it returns an
#In order traversal list. You can pass a function to traversal
#The tree as needed by client code
def traversalTree(self, traversalFunction = None, root = None):
if(traversalFunction is None):
#Returns a list of nodes in preOrder by default
# This function traversal the tree. By default it returns an
# In order traversal list. You can pass a function to traversal
# The tree as needed by client code
def traversalTree(self, traversalFunction=None, root=None):
if traversalFunction is None:
# Returns a list of nodes in preOrder by default
return self.__InOrderTraversal(self.root)
else:
#Returns a list of nodes in the order that the users wants to
# Returns a list of nodes in the order that the users wants to
return traversalFunction(self.root)
#Returns an string of all the nodes labels in the list
#In Order Traversal
# Returns an string of all the nodes labels in the list
# In Order Traversal
def __str__(self):
list = self.__InOrderTraversal(self.root)
str = ""
@ -185,6 +186,7 @@ class BinarySearchTree:
str = str + " " + x.getLabel().__str__()
return str
def InPreOrder(curr_node):
nodeList = []
if curr_node is not None:
@ -193,8 +195,9 @@ def InPreOrder(curr_node):
nodeList = nodeList + InPreOrder(curr_node.getRight())
return nodeList
def testBinarySearchTree():
r'''
r"""
Example
8
/ \
@ -203,15 +206,15 @@ def testBinarySearchTree():
1 6 14
/ \ /
4 7 13
'''
"""
r'''
r"""
Example After Deletion
7
/ \
1 4
'''
"""
t = BinarySearchTree()
t.insert(8)
t.insert(3)
@ -223,20 +226,20 @@ def testBinarySearchTree():
t.insert(4)
t.insert(7)
#Prints all the elements of the list in order traversal
# Prints all the elements of the list in order traversal
print(t.__str__())
if(t.getNode(6) is not None):
if t.getNode(6) is not None:
print("The label 6 exists")
else:
print("The label 6 doesn't exist")
if(t.getNode(-1) is not None):
if t.getNode(-1) is not None:
print("The label -1 exists")
else:
print("The label -1 doesn't exist")
if(not t.empty()):
if not t.empty():
print(("Max Value: ", t.getMax().getLabel()))
print(("Min Value: ", t.getMin().getLabel()))
@ -247,11 +250,12 @@ def testBinarySearchTree():
t.delete(6)
t.delete(14)
#Gets all the elements of the tree In pre order
#And it prints them
# Gets all the elements of the tree In pre order
# And it prints them
list = t.traversalTree(InPreOrder, t.root)
for x in list:
print(x)
if __name__ == "__main__":
testBinarySearchTree()