这是一个图形变换的程序，按字母“Y”画一个用点组成的圆；按字母“S”画一个用不同颜色填充的三角形；按字母“Z”画一个用不同颜色填充且带有边框图案的矩形；按“q”键退出。-this is　a image transform program,draw a cirlce according to the letter "Y"　draw a triangle filled with different color according to the letter"S" draw a edged figure with differnt color filled according to the letter "Z" press "q" to exit.