Python Data Structure 简明教程
Python - Search Tree
二叉搜索树 (BST) 是一棵树,其中所有节点都遵循以下属性。节点的左子树的键小于或等于其父节点的键。节点的右子树的键大于其父节点的键。因此,BST 将其所有子树分成两个部分;左子树和右子树
left_subtree (keys) ≤ node (key) ≤ right_subtree (keys)
Search for a value in a B-tree
在树中搜索值涉及将传入值与退出节点的值进行比较。在这里,我们也从左到右遍历节点,然后最终遍历父节点。如果搜索到的值与任何退出值不匹配,则我们返回找不到的消息,否则返回找到的消息。
Example
class Node:
def __init__(self, data):
self.left = None
self.right = None
self.data = data
# Insert method to create nodes
def insert(self, data):
if self.data:
if data < self.data:
if self.left is None:
self.left = Node(data)
else:
self.left.insert(data)
else data > self.data:
if self.right is None:
self.right = Node(data)
else:
self.right.insert(data)
else:
self.data = data
# findval method to compare the value with nodes
def findval(self, lkpval):
if lkpval < self.data:
if self.left is None:
return str(lkpval)+" Not Found"
return self.left.findval(lkpval)
else if lkpval > self.data:
if self.right is None:
return str(lkpval)+" Not Found"
return self.right.findval(lkpval)
else:
print(str(self.data) + ' is found')
# Print the tree
def PrintTree(self):
if self.left:
self.left.PrintTree()
print( self.data),
if self.right:
self.right.PrintTree()
root = Node(12)
root.insert(6)
root.insert(14)
root.insert(3)
print(root.findval(7))
print(root.findval(14))