基于递归的简单公式编辑器，可以输入仅含上标的迭代公式 公式的显示格式可以通过自定义常量编辑-Based on a simple recursive formula editor, you can enter on the subject of iteration formulas contain only the display format of the formula can be custom constants Editor

利用类模板编写的画矩形、圆等图形的函数，包含容器、迭代器等的用法-The use of class template written rectangle, circle and other graphics functions, including containers, iterators, and other usage