* 获取数字的第digit位（从右往左，0表示个位）
import { Scene, Circle, Square, Create, Transform, FadeOut } from 'manim-web';
，更多细节参见safew官方版本下载
For horizontal movement we can do even better. If your snake is moving to the right, we start by deleting every character on the left edge of the screen and inserting a new one on the right edge. After that, we do our patching (if needed). This automatically moves fruit into the correct position without us even needing to reprint it!。91视频对此有专业解读
// 从个位到最高位，逐位排序