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Added getNode function and made changes to insert function

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This commit is contained in:
Pablo 2017-10-22 20:13:06 -03:00
parent 535cbb76a3
commit 0ad029cb11
2 changed files with 193 additions and 36 deletions
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69
data_structures/Binary Tree/binary_seach_tree.py
View File

@ -2,7 +2,6 @@
A binary search Tree
'''
class Node:
def __init__(self, label):
@ -35,32 +34,49 @@ class BinarySearchTree:
self.root = None
def insert(self, label):
# Create a new Node
node = Node(label)
new_node = Node(label)
# If Tree is empty
if self.empty():
self.root = node
self.root = new_node
else:
dad_node = None
#If Tree is not empty
parent_node = None
curr_node = self.root
while True:
if curr_node is not None:
dad_node = curr_node
if node.getLabel() < curr_node.getLabel():
#While we don't get to a leaf
while curr_node is not None:
#We keep reference of the parent node
parent_node = curr_node
#If node label is less than current node
if new_node.getLabel() < curr_node.getLabel():
#We go left
curr_node = curr_node.getLeft()
else:
#Else we go right
curr_node = curr_node.getRight()
#We insert the new node in a leaf
if new_node.getLabel() < parent_node.getLabel():
parent_node.setLeft(new_node)
else:
if node.getLabel() < dad_node.getLabel():
dad_node.setLeft(node)
parent_node.setRight(new_node)
def getNode(self, label):
curr_node = None
#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 curr_node is not None and curr_node.getLabel() is not label:
#If node label is less than current node
if label < curr_node.getLabel():
#We go left
curr_node = curr_node.getLeft()
else:
dad_node.setRight(node)
break
#Else we go right
curr_node = curr_node.getRight()
return curr_node
def empty(self):
if self.root is None:
@ -69,15 +85,13 @@ class BinarySearchTree:
def preShow(self, curr_node):
if curr_node is not None:
print(curr_node.getLabel(), end=" ")
print(curr_node.getLabel())
self.preShow(curr_node.getLeft())
self.preShow(curr_node.getRight())
def getRoot(self):
return self.root
'''
Example
8
@ -89,6 +103,8 @@ Example
4 7 13
'''
if __name__ == "__main__":
t = BinarySearchTree()
t.insert(8)
t.insert(3)
@ -101,3 +117,14 @@ t.insert(14)
t.insert(13)
t.preShow(t.getRoot())
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):
print("The label -1 exists")
else:
print("The label -1 doesn't exist")

130
data_structures/Binary Tree/binary_search_tree.py Normal file
View File

@ -0,0 +1,130 @@
'''
A binary search Tree
'''
class Node:
def __init__(self, label):
self.label = label
self.left = None
self.right = None
def getLabel(self):
return self.label
def setLabel(self, label):
self.label = label
def getLeft(self):
return self.left
def setLeft(self, left):
self.left = left
def getRight(self):
return self.right
def setRight(self, right):
self.right = right
class BinarySearchTree:
def __init__(self):
self.root = None
def insert(self, label):
# Create a new Node
new_node = Node(label)
# If Tree is empty
if self.empty():
self.root = new_node
else:
#If Tree is not empty
parent_node = None
curr_node = self.root
#While we don't get to a leaf
while curr_node is not None:
#We keep reference of the parent node
parent_node = curr_node
#If node label is less than current node
if new_node.getLabel() < curr_node.getLabel():
#We go left
curr_node = curr_node.getLeft()
else:
#Else we go right
curr_node = curr_node.getRight()
#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)
def getNode(self, label):
curr_node = None
#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 curr_node is not None and curr_node.getLabel() is not label:
#If node label is less than current node
if label < curr_node.getLabel():
#We go left
curr_node = curr_node.getLeft()
else:
#Else we go right
curr_node = curr_node.getRight()
return curr_node
def empty(self):
if self.root is None:
return True
return False
def preShow(self, curr_node):
if curr_node is not None:
print(curr_node.getLabel())
self.preShow(curr_node.getLeft())
self.preShow(curr_node.getRight())
def getRoot(self):
return self.root
'''
Example
8
/ \
3 10
/ \ \
1 6 14
/ \ /
4 7 13
'''
if __name__ == "__main__":
t = BinarySearchTree()
t.insert(8)
t.insert(3)
t.insert(1)
t.insert(6)
t.insert(4)
t.insert(7)
t.insert(10)
t.insert(14)
t.insert(13)
t.preShow(t.getRoot())
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):
print("The label -1 exists")
else:
print("The label -1 doesn't exist")