#建立一個二叉樹
#聲明一個二叉樹節點類
#節點中包括:節點值,節點左子樹根節點,節點右子樹根節點,節點父節點
class TreeNode():
def __init__(self,value=None,leftNode=None,rightNode=None,parentNode=None):
self.val = value
self.leftnode = leftNode
self.rightnode = rightNode
self.parentnode = parentNode
def SetLeftNode(self,leftNode):
self.leftnode = leftNode
def SetRightNode(self,rightNode):
self.rightnode = rightNode
def SetParentNode(self,parentNode):
self.parentnode = parentNode
def GetLeftNode(self):
return self.leftnode
def GetRightNode(self):
return self.rightnode
def GetParentNode(self):
return self.parentnode
def GetValue(self):
return self.val
#定義根節點以及各個節點
root = TreeNode(1)
n2 = TreeNode(2)
n3 = TreeNode(3)
n4 = TreeNode(4)
n5 = TreeNode(5)
n6 = TreeNode(6)
n7 = TreeNode(7)
#設置根節點的左右節點
root.SetLeftNode(n2)
root.SetRightNode(n3)
#設置n2節點左右子樹節點和其父節點
n2.SetLeftNode(n4)
n2.SetRightNode(n5)
n2.SetParentNode(root)
#設置n3節點左右子樹節點和其父節點
n3.SetLeftNode(n6)
n3.SetRightNode(n7)
n3.SetParentNode(root)
#設置n4,n5節點的父節點
n4.SetParentNode(n2)
n5.SetParentNode(n2)
#設置n6,n7節點的父節點
n6.SetParentNode(n3)
n7.SetParentNode(n3)
#輸出n2節點值,n2節點左孩子值,n2節點右孩子值,n2節點父節點值
print(str('n2 node value:')+str(n2.GetValue()))
print(str('n2 left child value:')+str(n2.GetLeftNode().GetValue()))
print(str('n2 right child value:')+str(n2.GetRightNode().GetValue()))
print(str('n2 parent node value:')+str(n2.GetParentNode().GetValue()))
#前序遍歷二叉樹
def PreorderVisit(node):
if node == None:
return
print(node.GetValue())
PreorderVisit(node.GetLeftNode())
PreorderVisit(node.GetRightNode())
#中序遍歷二叉樹
def InorderVisit(node):
if node == None:
return
InorderVisit(node.GetLeftNode())
print(node.GetValue())
InorderVisit(node.GetRightNode())
#後續遍歷二叉樹
def PostorderVisit(node):
if node == None:
return
PostorderVisit(node.GetLeftNode())
PostorderVisit(node.GetRightNode())
print(node.GetValue())
#調用前序,中序,後續遍歷函數輸出遍歷結果
print('Preorder Visit Binary Tree:')
PreorderVisit(root)
print('Inorder Visit Binary Tree:')
InorderVisit(root)
print('Postorder Visit Binary Tree:')
PostorderVisit(root)