用C#编写（输入三个整数，然后输出三个数中居中的数，并输出其阶乘）的程序（三种方法）

题目：让用户自行输入三个整数，然后输出三个数中居中的数，并输出其阶乘。

//第一种方法

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ConsoleApplication2{class Program{static void Main(string[] args){while (true){Console.WriteLine(\"请输入三个数，用回车键确认\");int a = int.Parse(Console.ReadLine());int b = int.Parse(Console.ReadLine());int c = int.Parse(Console.ReadLine());int middle = 0;//a是中间值，则有两种情况，b是最小值或b是最大值//b同//c同if ((a >= b && a <= c) || (a >= c && a <= b)){Console.WriteLine(\"这三个数中间数是{0}\", a);middle = a;}if (b >= a && b <= c || b >= c && b <= a){Console.WriteLine(\"这三个数中间数是{0}\", b);middle = b;}if (c >= a && c <= b || c >= b && c <= a){Console.WriteLine(\"这三个数中间数是{0}\", c);middle = c;}double result = 1;for (int i = 1; i <= middle; i++){result *= i;}Console.WriteLine(\"它的阶乘是\" + result);}Console.ReadKey();}}}

//第二种方法
第二种方法与第三种方法区别在于应用了return的两种不同形式，第二种方法是double类型，有返回值，第三种方法是void类型，无返回值，两者调用方法不同。

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ConsoleApplication10{class Program{static void Main(string[] args){Console.WriteLine(\"请输入三个数，用回车键确认\");int a = int.Parse(Console.ReadLine());int b = int.Parse(Console.ReadLine());int c = int.Parse(Console.ReadLine());if(a<b){if(b<c){Console.WriteLine(\"这三个数中间数是{0}\",b);Console.WriteLine(\"此数阶乘为{0}\", jiechen(b));}else if(c>a){Console.WriteLine(\"这三个数中间数是{0}\", c);Console.WriteLine(\"此数阶乘为{0}\", jiechen(c));}else{Console.WriteLine(\"这三个数中间数是{0}\", a);Console.WriteLine(\"此数阶乘为{0}\", jiechen(a));}}else if(b>c){Console.WriteLine(\"这三个数中间数是{0}\", b);Console.WriteLine(\"此数阶乘为{0}\", jiechen(b));}else if(c>a){Console.WriteLine(\"这三个数中间数是{0}\", a);Console.WriteLine(\"此数阶乘为{0}\", jiechen(a));}else{Console.WriteLine(\"这三个数中间数是{0}\", c);Console.WriteLine(\"此数阶乘为{0}\", jiechen(c));}Console.ReadKey();}static double jiechen(int j){double p = 1;for (int i = j; i>0; i--){p *= i;}return p;}}}

//第三种方法

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ConsoleApplication1{class Program{static void Main(string[] args){Console.WriteLine(\"请输入三个数，用回车键确认\");int a = int.Parse(Console.ReadLine());int b = int.Parse(Console.ReadLine());int c = int.Parse(Console.ReadLine());if (a < b){if (b < c){Console.WriteLine(\"这三个数中间数是{0}\", b);jiechen(b);}else if (c > a){Console.WriteLine(\"这三个数中间数是{0}\", c);jiechen(c);}else{Console.WriteLine(\"这三个数中间数是{0}\", a);jiechen(a);}}else if (b > c){Console.WriteLine(\"这三个数中间数是{0}\", b);jiechen(b);}else if (c > a){Console.WriteLine(\"这三个数中间数是{0}\", a);jiechen(a);}else{Console.WriteLine(\"这三个数中间数是{0}\", c);jiechen(c);}Console.ReadKey();}static void jiechen(int j){double p = 1;for (int i = j; i > 0; i--){p *= i;}Console.WriteLine(\"此数阶乘为{0}\", p);return;}}}