2020/2/6数据结构二叉树

class TreeNode: 
    def __init__(self,data=None,left=None,right=None):
        self.data=data
        self.left=left
        self.right=right
class Bitree: 
    def __init__(self,root=None):
        self.root=root
       
    def is_empty(self):
        if self.root is None:
            return True
        else:
            return False
    
    def preOrder(self,node):
        if node is None:
            return
        print(node.data)
        self.preOrder(node.left)
        self.preOrder(node.right)
          
    def inOrder(self,node):
        if node is None:
            return
        self.inOrder(node.left)
        print(node.data, end="")
        self.inOrder(node.right)
    def postOrder(self,node):
        if node is None:
            return
        self.postOrder(node.left)
        self.postOrder(node.right)
        print(node.data,end="")
     def levelOrder(self,node):
        qu=SQueue()
        qu.enqueue(node)
        while not qu.is_empty():
            node=qu.dequeue()
            print(node.data)
            if node.left:
                qu.enqueue(node.left)
            if node.right:
                qu.enqueue(node.right)