【算法】【python实现】二叉树深度、广度优先遍历

# 定义二叉树节点
class TreeNode(object):
    def __init__(self,val,left=None,right=None):
        self.val=val
        self.left=left
        self.right=right

#定义二叉树类
class BinaryTree(object):
    def __init__(self,root=None):
        self.root=root

    def preOrder(self,retList=[],node=‘root‘):
        if node!=None:
            retList.append(node)
            self.preOrder(retList,node.left)　　　　# 递归调用，将左子节点放到列表里　　
            self.preOrder(retList,node.right)　　  # 递归调用，将右节点放到列表里　　
        return retList

    def inOrder(self,retList=[],node=‘root‘):
        if node!=None:
            self.inOrder(retList,node.left)
            retList.append(node)
            self.inOrder(retList,node.right)
        return retList
    def postOrder(self,retList=[],node=‘root‘):
        if node!=None:
            self.postOrder(retList,node.left)
            self.postOrder(retList,node.right)
            retList.append(node)
        return retList
                     

if __name__==‘__main__‘:
    rootNode=TreeNode(50)
    rootNode.left = TreeNode(20,left=TreeNode(15),right=TreeNode(30))
    rootNode.right = TreeNode(60,right=TreeNode(70))
    binaryTree=BinaryTree(rootNode)
    ret = binaryTree.preOrder([],binaryTree.root)
    for i in ret:
        print(i.val,end=‘.‘)
    print(‘\n‘+‘-‘*20)
    ret = binaryTree.inOrder([],binaryTree.root)
    for i in ret:
        print(i.val,end=‘.‘)
    print(‘\n‘+‘-‘*20)
    ret = binaryTree.postOrder([],binaryTree.root)
    for i in ret:
        print(i.val,end=‘.‘)