mirror of
https://github.com/krahets/hello-algo.git
synced 2025-07-07 23:04:55 +08:00
add binary_tree and avl_tree python code
This commit is contained in:
@ -1,10 +1,80 @@
|
||||
'''
|
||||
"""
|
||||
File: binary_tree_dfs.py
|
||||
Created Time: 2022-11-25
|
||||
Author: Krahets (krahets@163.com)
|
||||
'''
|
||||
"""
|
||||
|
||||
import sys, os.path as osp
|
||||
sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
|
||||
from include import *
|
||||
|
||||
|
||||
result = []
|
||||
|
||||
|
||||
def preOrder(root):
|
||||
"""
|
||||
前序遍历二叉树
|
||||
"""
|
||||
if root is None:
|
||||
return
|
||||
|
||||
# 访问优先级:根结点 -> 左子树 -> 右子树
|
||||
result.append(root.val)
|
||||
preOrder(root=root.left)
|
||||
preOrder(root=root.right)
|
||||
|
||||
|
||||
def inOrder(root):
|
||||
"""
|
||||
中序遍历二叉树
|
||||
"""
|
||||
if root is None:
|
||||
return
|
||||
|
||||
# 访问优先级:左子树 -> 根结点 -> 右子树
|
||||
inOrder(root=root.left)
|
||||
result.append(root.val)
|
||||
inOrder(root=root.right)
|
||||
|
||||
|
||||
def postOrder(root):
|
||||
"""
|
||||
后序遍历二叉树
|
||||
"""
|
||||
if root is None:
|
||||
return
|
||||
|
||||
# 访问优先级:左子树 -> 右子树 -> 根结点
|
||||
postOrder(root=root.left)
|
||||
postOrder(root=root.right)
|
||||
result.append(root.val)
|
||||
|
||||
|
||||
""" Driver Code """
|
||||
if __name__ == "__main__":
|
||||
# 初始化二叉树
|
||||
# 这里借助了一个从数组直接生成二叉树的函数
|
||||
root = list_to_tree(
|
||||
arr=[1, 2, 3, 4, 5, 6, 7, None, None, None, None, None, None, None, None]
|
||||
)
|
||||
print("\n初始化二叉树\n")
|
||||
print_tree(root)
|
||||
|
||||
# 前序遍历
|
||||
result = []
|
||||
preOrder(root)
|
||||
print("\n前序遍历的结点打印序列 = ", result)
|
||||
assert result == [1, 2, 4, 5, 3, 6, 7]
|
||||
|
||||
# 中序遍历
|
||||
result = []
|
||||
inOrder(root)
|
||||
print("\n中序遍历的结点打印序列 = ", result)
|
||||
assert result == [4, 2, 5, 1, 6, 3, 7]
|
||||
|
||||
# 后序遍历
|
||||
result = []
|
||||
postOrder(root)
|
||||
print("\n后序遍历的结点打印序列 = ", result)
|
||||
assert result == [4, 5, 2, 6, 7, 3, 1]
|
Reference in New Issue
Block a user