using System;

namespace rendom
{
    class Rand
    {
        private long seed;  //随机数种子

        //用系统时间作为随机种子
        public Rand()
        {
            string str=DateTime.Now.Day.ToString();
            str+=DateTime.Now.Hour.ToString();
            str+=DateTime.Now.Minute.ToString();
            str+=DateTime.Now.Second.ToString();
            str+=DateTime.Now.Millisecond.ToString();
            this.seed=long.Parse(str);
        }
        //用户自定义随机种子
        public Rand(long Value)
        {
            this.seed=Value;
        }
        //产生非负伪随机数
        public long Next()
        {
            long l=this.seed;        
            l=l*l;
            string strTime = l.ToString();
            int w=strTime.Length/3;
            string str=\"\";
            for(int i=w;i<strTime.Length-w;i++)
                str+=strTime[i];
            l=long.Parse(str);
            return l;
        }
        //产生上限为Value的伪随机数
        public long Next(long Value)
        {
            if(Value<0)
                return -1;
            long l=this.seed;
            l=l*l;
            string strTime = l.ToString();
            int w=strTime.Length/3;
            string str=\"\";
            for(int i=w;i<strTime.Length-w;i++)
                str+=strTime[i];
            l=long.Parse(str);
            return l%Value;
        }
        //产生下限为minValue上限为maxValue的伪随机数
        public long Next(long minValue,long maxValue)
        {
            if(minValue<0 || maxValue<0 || minValue>maxValue)
                return -1;
            long l=this.seed;        
            l=l*l;
            string strTime = l.ToString();
            int w=strTime.Length/3;
            string str=\"\";
            for(int i=w;i<strTime.Length-w;i++)
                str+=strTime[i];
            l=long.Parse(str);
            return l%(maxValue-minValue)+minValue;       
        }
        //伪随机数填充指定的比特数组
        public void NextBytes(byte []buffer)
        {
            long Value = 0;
            Value=this.Next()%255;        
            for(int i=0;i<buffer.Length;i++)
            {    
                Value=Value*Value;        
                string strTime = Value.ToString();
                int w=strTime.Length/3;
                string str=\"\";
                for(int j=w;j<strTime.Length-w;j++)
                    str+=strTime[j];
                Value=long.Parse(str);
                Value=Value%255;
                buffer[i]=(byte)Value;
            }
        }
        //产生0.0到1.0的伪随机数
        public double NextDouble()
        {
            long l=this.Next(0,100000);
            if(l==100000)
                return 1.0;
            l=l*l;
            string strTime=l.ToString();
            int w=strTime.Length/3;
            string str = \"0.\";
            for(int i=w;i<strTime.Length-w;i++)
                str+=strTime[i];
            double d=double.Parse(str);
            return d;
        }    
    }
    class AppMain
    {
        static int Main()
        {
            Rand rand=new Rand();
            //产生伪随机数
            long n=rand.Next();
            Console.WriteLine(n.ToString());
            //产生100内的伪随机数
            n=rand.Next(100);
            Console.WriteLine(n.ToString());
            //产生20到30之间的伪随机数
            n=rand.Next(20,30);
            Console.WriteLine(n.ToString());
            //产生0.0到1.0之间的伪随机数
            b=rand.NextDouble();
            Console.WriteLine(b.ToString());
            Console.ReadLine();
        }
    }
}

[此贴子已经被作者于2007-5-9 11:25:15编辑过]