用户输入一个形式为y=x^m+z^n的函数，当然x和z的次数可以任意，并且可以有多个。程序将画出这个函数表示的图像。-The user to enter a form of y = x ^ m+ Z ^ n function, of course, the number of x and z can be arbitrary, and can have more than one. Process will draw the function of images.