一霎微雨洒庭轩

2007-08-23

随机算法求圆周率 - [Algorithms]

版权声明：转载时请以超链接形式标明文章原始出处和作者信息及本声明
http://conoon.blogbus.com/logs/7872522.html

using System;
using System.Collections.Generic;
using System.Collections;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void count(Random rand)
        {
            Console.Write("请输入运算的次数：");
          
            Int32  N = 0;
            Int32 K = 0;
            try
            {
                string strinput = Console.ReadLine();
                Int32 M = Convert.ToInt32(strinput);
              
                for (Int32 i = 0; i < M; i++)
                {
                    double x = rand.NextDouble();
                    double y = rand.NextDouble();

                    if (x * x + y * y <= 1)
                    {
                        N++;
                       
                        if (x + y >= 1) K++;
                    }
                   
                }
              
                double result1 = (double)4 * N / M;
                Int32 J = M - N;
                double result2=(double)(4*K+2*J)/(K+J);
                double wucha1=result1-System.Math.PI;
                double wucha2 = result2 -System.Math.PI;
                Console.ForegroundColor = ConsoleColor.Green;
                Console.WriteLine("经过{0}次随机事件后，算法1圆周率为{1},误差为{2}.", M, result1,wucha1);
                Console.WriteLine("经过{0}次随机事件后，算法2圆周率为{1},误差为{2}.\n", M, result2,wucha2 );
                Console.ForegroundColor = ConsoleColor.White;
            }
            catch {
                Console.ForegroundColor = ConsoleColor.Gray;
                Console.Write("输入有误,");
            }
        }

    
        static void Main(string[] args)
        {
            Console.WriteLine("****************************");
            Console.WriteLine("随机算法求圆周率演示程序\n");
            Console.WriteLine("****************************\n");
            Console.ForegroundColor = ConsoleColor.White;
            Random rand = new Random();
            while (true)
            {                
                count(rand);            
            }
        }
    }
}