C# 实现阶乘 (递归,非递归) 实现代码

//main:

using system;
using system.collections.generic;
using system.linq;
using system.text;

namespace factorial
{
    class program
    {
        static void main(string[] args)
        {
            function obj = new function();
            console.writeline("would you like to know which number of factorial：");
            int number = convert.toint32(console.readline());
            console.writeline();
            console.write("the fibonacci of {0} is：{1}", number, obj.factorial(number));
            console.writeline();
            console.write("the factorialrecursion of {0} is：{1}", number, obj.factorialrecursion(number));
            console.readkey();
        }
    }
}

 //class:
 

 using system;
using system.collections.generic;
using system.linq;
using system.text;

namespace factorial
{
    class function
    {
        /// <summary>
        /// factorial定义为：
        ///      ┌ 1        n=0      
        ///   n!=│
        ///      └ n(n-1)!  n>0
        /// </summary>
        /// <param name="number"></param>
        /// <returns></returns>
        public int factorial(int number)
        {
            if (number != 0)
            {
                return number * factorial(number - 1);
            }
            else if (number == 0)
            {
                return 1;
            }
            return number;
        }

        public int factorialrecursion(int number)
        {
            int f = 1;
            for (int i = 1; i <= number; i++)
            {
                f *= i;
            }
            return f;
        }
    }
}

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