Python用turtle可视化二叉树中序遍历

可以使用Python中的turtle库来可视化二叉树的中序遍历。具体实现步骤如下：

1. 首先，导入turtle库和random库，并定义一个Node类表示二叉树的节点。

import turtle
import random

class Node:
    def __init__(self, value):
        self.left = None
        self.right = None
        self.value = value

2. 定义一个函数draw_node，用于在窗口上绘制一个二叉树节点。该函数接受四个参数：x、y表示节点的坐标，size表示节点的大小，color表示节点的颜色。

def draw_node(x, y, size, color):
    turtle.penup()
    turtle.goto(x, y)
    turtle.pendown()
    turtle.fillcolor(color)
    turtle.begin_fill()
    turtle.circle(size)
    turtle.end_fill()
    turtle.penup()
    turtle.goto(x, y - size * 1.2)
    turtle.write(str(value), align="center", font=("Arial", 12, "normal"))

3. 定义一个函数inorder，用于进行二叉树的中序遍历，并在遍历的过程中绘制节点。该函数接受两个参数：root表示二叉树的根节点，x表示根节点的横坐标。

def inorder(root, x):
    if root is not None:
        inorder(root.left, x - 50)
        draw_node(x, 0, 20, "blue")
        turtle.penup()
        turtle.goto(x, 50)
        turtle.pendown()
        turtle.goto(x, 20)
        turtle.penup()
        turtle.goto(x - 20, -20)
        turtle.write(str(root.value), align="center", font=("Arial", 12, "normal"))
        inorder(root.right, x + 50)

4. 最后，生成一个随机的二叉树，并调用inorder函数进行中序遍历。设置turtle窗口的大小，并隐藏turtle的箭头。

root = Node(random.randint(0, 100))
for i in range(20):
    node = Node(random.randint(0, 100))
    current = root
    while True:
        if node.value < current.value:
            if current.left is None:
                current.left = node
                break
            else:
                current = current.left
        else:
            if current.right is None:
                current.right = node
                break
            else:
                current = current.right

turtle.setup(width=800, height=600)
turtle.hideturtle()
inorder(root, 400)

完整代码如下：

import turtle
import random

class Node:
    def __init__(self, value):
        self.left = None
        self.right = None
        self.value = value

def draw_node(x, y, size, color):
    turtle.penup()
    turtle.goto(x, y)
    turtle.pendown()
    turtle.fillcolor(color)
    turtle.begin_fill()
    turtle.circle(size)
    turtle.end_fill()
    turtle.penup()
    turtle.goto(x, y - size * 1.2)
    turtle.write(str(value), align="center", font=("Arial", 12, "normal"))

def inorder(root, x):
    if root is not None:
        inorder(root.left, x - 50)
        draw_node(x, 0, 20, "blue")
        turtle.penup()
        turtle.goto(x, 50)
        turtle.pendown()
        turtle.goto(x, 20)
        turtle.penup()
        turtle.goto(x - 20, -20)
        turtle.write(str(root.value), align="center", font=("Arial", 12, "normal"))
        inorder(root.right, x + 50)

root = Node(random.randint(0, 100))
for i in range(20):
    node = Node(random.randint(0, 100))
    current = root
    while True:
        if node.value < current.value:
            if current.left is None:
                current.left = node
                break
            else:
                current = current.left
        else:
            if current.right is None:
                current.right = node
                break
            else:
                current = current.right

turtle.setup(width=800, height=600)
turtle.hideturtle()
inorder(root, 400)