12.27每日总结

using System;

 

using System;

 

using System.Collections.Generic;

 

using System.Linq;

 

using System.Text;

 

namespace 实验1_1

 

{

 

    class Program

 

    {

 

        static void Main(string[] args)

 

        {

 

            int i; double t_1, t_2, t_3; double r_lenth, r_width; double cir, area;   //三角形及长方形的变量等

 

            while (true)

 

            {

 

                Console.WriteLine("       1.三角形     2.长方形    3.退出          ");

 

                Console.WriteLine("请输入序号：");

 

                i = int.Parse(Console.ReadLine());

 

                switch (i)

 

                {

 

                    case 1:           //三角形周长及面积算法

 

                        Console.WriteLine("请输入最短边边长：");//用户依次输入三个边长

 

                        t_1 = float.Parse(Console.ReadLine());

 

                        Console.WriteLine("请输入中间边长：");

 

                        t_2 = float.Parse(Console.ReadLine());

 

                        Console.WriteLine("请输入最长的边长：");

 

                        t_3 = float.Parse(Console.ReadLine());//输入结束

 

                        if (t_1 + t_2 <= t_3)

 

                        {

 

                            Console.WriteLine("输入边长错误");

 

                            break;

 

                        }

 

                        cir = t_1 + t_2 + t_3;                //计算三角形周长及面积

 

                        area = Math.Sqrt(cir / 2 * (cir / 2 - t_1) * (cir / 2 - t_2) * (cir / 2 - t_3));//无法将double隐式转换为float,之前用的float类型的边长等,sqrt函数返回为double

 

                        Console.WriteLine("该三角形周长为：{0}", cir);

 

                        Console.WriteLine("该三角形面积为：{0}", area);

 

                        break;

 

                    case 2:                                    //长方形周长及面积算法

 

                        Console.WriteLine("请输入长方形的长：");//用户依次输入三个边长

 

                        r_lenth = float.Parse(Console.ReadLine());

 

                        Console.WriteLine("请输入长方形的宽：");

 

                        r_width = float.Parse(Console.ReadLine());

 

                        cir = 2 * (r_lenth + r_width);        //长方形周长及面积

 

                        area = r_lenth * r_width;

 

                        Console.WriteLine("该长方形周长为：{0}", cir);

 

                        Console.WriteLine("该长方形面积为：{0}", area);

 

                        break;

 

                    case 3: Console.WriteLine("欢迎您的下次进入！！！"); break;

 

                    default: Console.WriteLine("输入错误！！！"); break;

 

                }//switch结束

 

                if (i == 3) break; //判断用户是否退出系统

 

            }//while循环结束

 

        }

 

    }

 

}