趣味菜单

1、设计菜单

给出3个菜单项的内容和输入提示：

1．解一元二次方程 2. 出圈游戏

3. 退出程序

2、解一元二次方程要求：编制一个求方程ax2+bx+c=0的根的程序。一般将系数设成floa t型，可以把变量设成double型，使用库函数sqrt()在头文件math.h中定义 。

3、出圈游戏的要求：使用约瑟夫环游戏。这里假设有人数为n个人的一个小组，他们按顺时针方向围坐一圈。一开始任选一个正整数作为报数上限值m，从第一个人开始按顺时针方向自1开始顺序报数，报到m时停止报数。报数m的人出列，然后从他原来所在的、顺时针方向的下一个人开始重新从1报数，报到m时停止报数并出列。如此下去，直到所有人全部出列为止。要求按他们出列的顺序输出他们的名字。

-Funny menu

1, design the menu

Given 3 menu item content and input prompt:

1 solution of one dollar two times equation 2 out of ring games

3 exit program

In 2, one yuan two equations requirements : the preparation of a equation ax2+bx+c = 0 for the root of the procedure. The coefficient is set to floa T, can have variable set into type double, use the library function sqrt ( ) in the header file defined in math.h.

In 3, the circle game requirements : the use of the Joseph ring game. This hypothesis has number for n individuals in a group, they are in a clockwise direction around a circle. The beginning of a positive integer as the number of upper limit of M, from the first individual to start a clockwise from 1 to start the sequence number off, the report m stop. Reported m out from him, then the original, a clockwise direction on the next person to start off again from the 1 number off, the report m stop and the column. And so on, until all of the column until all. According to t