Random

生成0~100之间的随机数

import java.util.Random; 
public class RandomNum {
    public static void main(String[] args)
    {
        int i,j;
        Random r =new java.util.Random(10);
        for(j=0;j<10;j++)
        {
            for(i=0;i<10;i++)
            {
                System.out.printf("%3d ", r.nextInt(100));
            }
            System.out.print("\n");
        }
    }
}

生成[0,1]之间均匀分布的随机数

public class RandomNum {
    static double rand01(double[] r)
    {
        double base,u,v,p,t1,t2,t3;
        base=256.0;
        u=17.0;
        v=139.0;
        
        t1=u*(r[0])+v;
        t2=(int)(t1/base);
        t3=t1-t2*base;
        r[0]=t3;
        p=r[0]/base;
        
        return p;
    }
    public static void main(String[] args)
    {
        int i;
        double[] r= {5.0};
            for(i=0;i<10;i++)
            {
                System.out.printf("%10.5f\n", rand01(r));
            }
            System.out.print("\n");

    }
}

产生任意范围的随机数(范围：[m,n])

public class RandomNum {
    static double rand01(double[] r)
    {
        double base,u,v,p,t1,t2,t3;
        base=256.0;
        u=17.0;
        v=139.0;
        
        t1=u*(r[0])+v;
        t2=(int)(t1/base);
        t3=t1-t2*base;
        r[0]=t3;
        p=r[0]/base;
        
        return p;
    }
    public static void main(String[] args)
    {
        int i;
        double m,n;
        m=10.0;
        n=20.0;
        double[] r= {5.0};
            for(i=0;i<10;i++)
            {
                System.out.printf("%10.5f\n", m+(n-m)*rand01(r));
            }
            System.out.print("\n");

    }
}

[m,n]之间均匀分布的随机整数算法

public class RandomNum {
    static double rand01(double[] r)
    {
        double base,u,v,p,t1,t2,t3;
        base=256.0;
        u=17.0;
        v=139.0;
        
        t1=u*(r[0])+v;
        t2=(int)(t1/base);
        t3=t1-t2*base;
        r[0]=t3;
        p=r[0]/base;
        
        return p;
    }
    public static void main(String[] args)
    {
        int i,m,n;
        m=100;
        n=200;
        double[] r= {5.0};
            for(i=0;i<10;i++)
            {
                System.out.printf("%d\n", m+(int)((n-m)*rand01(r)));
            }
            System.out.print("\n");

    }
}

正态分布的随机数生成

public class RandomNum {
    static double rand01(double[] r)
    {
        double base,u,v,p,t1,t2,t3;
        base=256.0;
        u=17.0;
        v=139.0;
        
        t1=u*(r[0])+v;
        t2=(int)(t1/base);
        t3=t1-t2*base;
        r[0]=t3;
        p=r[0]/base;
        
        return p;
    }
    static double randZT(double u,double t,double[] r) {
        int i;
        double total=0.0;
        double result;
        for(i=0;i<12;i++)
        {
            total+=rand01(r);
        }
        result=u+t*(total-6.0);
        return result;
    }
    
    public static void main(String[] args)
    {
        int i;
        double u=2.0;
        double t=3.5;
        double[] r= {5.0};
            for(i=0;i<10;i++)
            {
                System.out.printf("%10.5f\n", randZT(u,t,r));
            }
            System.out.print("\n");

    }
}