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Copy pathbinary_tree.py
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229 lines (177 loc) · 5.61 KB
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class Node(object):
def __init__(self, value):
self.value = value
self.left = None
self.right = None
class BinaryTree(object):
def __init__(self, root):
self.root = Node(root)
def print_tree(self, traversal_type):
if traversal_type == "preorder":
return self.preorder_print(tree.root, "")
elif traversal_type == "inorder":
return self.inorder_print(tree.root, "")
elif traversal_type == "postorder":
return self.postorder_print(tree.root, "")
elif traversal_type == "levelorder":
return self.levelorder_print(tree.root)
elif traversal_type == "reverse_levelorder":
return self.reverse_levelorder_print(tree.root)
else:
print("Traversal type " + str(traversal_type) + " is not supported.")
return False
def preorder_print(self, start, traversal):
"""Root->Left->Right"""
if start:
traversal += (str(start.value) + "-")
traversal = self.preorder_print(start.left, traversal)
traversal = self.preorder_print(start.right, traversal)
return traversal
def inorder_print(self, start, traversal):
"""Left->Root->Right"""
if start:
traversal = self.inorder_print(start.left, traversal)
traversal += (str(start.value) + "-")
traversal = self.inorder_print(start.right, traversal)
return traversal
def postorder_print(self, start, traversal):
"""Left->Right->Root"""
if start:
traversal = self.postorder_print(start.left, traversal)
traversal = self.postorder_print(start.right, traversal)
traversal += (str(start.value) + "-")
return traversal
def levelorder_print(self, start):
if start is None:
return
queue = Queue()
queue.enqueue(start)
traversal = ""
while len(queue) > 0:
traversal += str(queue.peek()) + "-"
node = queue.dequeue()
if node.left:
queue.enqueue(node.left)
if node.right:
queue.enqueue(node.right)
return traversal
def reverse_levelorder_print(self, start):
if start is None:
return
queue = Queue()
stack = Stack()
queue.enqueue(start)
traversal = ""
while len(queue) > 0:
node = queue.dequeue()
stack.push(node)
if node.right:
queue.enqueue(node.right)
if node.left:
queue.enqueue(node.left)
while len(stack) > 0:
node = stack.pop()
traversal += str(node.value) + "-"
return traversal
def _height(self,node):
if not node:
return -1
lh = self._height(node.left)
rh = self._height(node.right)
return 1 + max(lh,rh)
def _size(self,node,s):
if not node:
return 0
s = s+1
if node.left:
s = self._size(node.left,s)
if node.right:
s = self._size(node.right,s)
return s
def _size_itr(self,node):
if not node:
return 0
s = Stack()
s.push(node)
total = 0
while len(s) > 0 :
n = s.pop()
total += 1
if n.left:
s.push(n.left)
if n.right:
s.push(n.right)
return total
def get_height(self):
return self._height(self.root)
def get_size(self):
return self._size(self.root,0)
class Queue(object):
def __init__(self):
self.items = []
def enqueue(self, item):
self.items.insert(0, item)
def dequeue(self):
if not self.is_empty():
return self.items.pop()
def is_empty(self):
return len(self.items) == 0
def peek(self):
if not self.is_empty():
return self.items[-1].value
def __len__(self):
return self.size()
def size(self):
return len(self.items)
class Stack(object):
def __init__(self):
self.items = []
def __len__(self):
return self.size()
def size(self):
return len(self.items)
def push(self, item):
self.items.append(item)
def pop(self):
if not self.is_empty():
return self.items.pop()
def peek(self):
if not self.is_empty():
return self.items[-1]
def is_empty(self):
return len(self.items) == 0
def __str__(self):
s = ""
for i in range(len(self.items)):
s += str(self.items[i].value) + "-"
return s
# 1-2-4-5-3-6-7-
# 4-2-5-1-6-3-7
# 4-2-5-6-3-7-1
# 1
# / \
# 2 3
# / \ / \
# 4 5 6 7
# Set up tree:
tree = BinaryTree(1)
tree.root.left = Node(2)
tree.root.right = Node(3)
tree.root.left.left = Node(4)
tree.root.left.right = Node(5)
tree.root.right.left = Node(6)
tree.root.right.right = Node(7)
tree.root.right.right.right = Node(7)
tree.root.right.right.right.right = Node(7)
print(tree.print_tree("preorder"))
print(tree.print_tree("inorder"))
print(tree.print_tree("postorder"))
print(tree.print_tree("levelorder"))
print(tree.print_tree("reverse_levelorder"))
###############################
# Find height of Tree
print("height of tree is",tree.get_height())
###############################
# Find size of Tree ( total of all node )
print("size / total node in tree is",tree.get_size())
print("size / total node in tree using iter ",tree._size_itr(tree.root))