tree.py 文件源码

def drawtree(root):
    def height(root):
        return 1 + max(height(root.left), height(root.right)) if root else -1

    def jumpto(x, y):
        t.penup()
        t.goto(x, y)
        t.pendown()

    def draw(node, x, y, dx):
        if node:
            t.goto(x, y)
            jumpto(x, y - 20)
            t.write(node.val, align='center', font=('Arial', 12, 'normal'))
            draw(node.left, x - dx, y - 60, dx / 2)
            jumpto(x, y - 20)
            draw(node.right, x + dx, y - 60, dx / 2)

    import turtle
    t = turtle.Turtle()
    t.speed(0)
    turtle.delay(0)
    h = height(root)
    jumpto(0, 30 * h)
    draw(root, 0, 30 * h, 40 * h)
    t.hideturtle()
    turtle.mainloop()