randomtest.java

《Java核心技术应用开发》电子工业出版社书籍源代码

package sample;
import java.util.Random;
class RandomTest {
  public static void main(String args[]) {
    Random r = new Random();
    double val;
    double sum = 0;
    int bell[] = new int[10];
    for(int i=0; i<100; i++) {
      val = r.nextGaussian();
      sum += val;
      double t = -2;
      for(int x=0; x<10; x++, t += 0.5)
        if(val < t) {
          bell[x]++;
          break;
        }
   }
   System.out.println("Average of values: " +(sum/100));
   // display bell curve, sideways
   for(int i=0; i<10; i++) {
    for(int x=bell[i]; x>0; x--)
     System.out.print("*");
    System.out.println();
  }
 }
}