基于easyx动态建立二叉树

基于easyx动态建立二叉树的方法如下：

import easygraphics as eg

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

def draw_tree(node, x, y, level):
    if node is None:
        return
    radius = 20
    eg.draw_circle(x, y, radius)
    eg.draw_text(x - radius, y - radius, str(node.value))
    if node.left is not None:
        x_left = x - 2 ** (5 - level) * radius
        y_left = y + 80
        eg.draw_line(x, y + radius, x_left, y_left - radius)
        draw_tree(node.left, x_left, y_left, level + 1)
    if node.right is not None:
        x_right = x + 2 ** (5 - level) * radius
        y_right = y + 80
        eg.draw_line(x, y + radius, x_right, y_right - radius)
        draw_tree(node.right, x_right, y_right, level + 1)

def main():
    root = TreeNode(1)
    root.left = TreeNode(2)
    root.right = TreeNode(3)
    root.left.left = TreeNode(4)
    root.left.right = TreeNode(5)
    root.right.left = TreeNode(6)
    root.right.right = TreeNode(7)

    eg.init_graph(600, 600)
    eg.set_render_mode(eg.RenderMode.RENDER_MANUAL)
    eg.set_fill_color(eg.COLOR_WHITE)
    eg.clear_device()
    draw_tree(root, 300, 50, 1)
    eg.render()
    eg.getch()
    eg.close_graph()

if __name__ == '__main__':
    main()

这段代码使用了easygraphics库来绘制二叉树。首先定义了一个TreeNode类来表示二叉树的节点，然后使用递归的方式绘制二叉树。在绘制过程中，根据节点的位置和层级来确定节点的坐标，并使用圆形和线段来表示节点和连接关系。最后通过调用`eg.render()`来显示绘制结果。