一个程序动态分配一个浮点空间,输入一个数和到该空间中,计算以该数为半径的圆的面积并在屏幕上显示,最后释放该空间。-A program dynamically allocates space for a floating-point, enter a number and to the space, calculated on the number and area of a circle radius of the screen, and finally release the space.