经典画圆程序，C语言版，建立了坐标系，用户只需要输入圆的半径。-classic Circle procedures, C language version, a coordinate system, the user need only input the circular radius.

经典c语言鼠标编程，非常实用，是学习鼠标编程的好程序 -classic mouse c programming language, very practical, mouse study is a good programming procedures