Java小程序求圆的周长和面积实例

/** * auther 司机 */import java.util.Scanner; public class Test011 {  static double MontePI(int n) {   double PI;   double x, y;   int i, sum;   sum = 0;   for (i = 1; i < n; i++) {    x = Math.random();    y = Math.random();    if ((x * x + y * y) <= 1) {    sum++;    }   }   PI = 4.0 * sum / n;   return PI;  }  public static void main(String[] args) {   int n;   double PI;   System.out.println("蒙特卡洛概率算法计算圆周率:");   Scanner input = new Scanner(System.in);   System.out.println("输入点的数量：");   n = input.nextInt();   PI = MontePI(n);   System.out.println("PI="+PI);      double radius;   double area;   double circle;   Scanner input2 = new Scanner(System.in);   System.out.println("输入圆半径");   radius = input2.nextInt();   circle = 2*PI*radius;   area = radius*radius*PI;   System.out.println("The area is"+ area);   System.out.println("The circle is"+ circle);  } }

蒙特卡洛概率算法计算圆周率:输入点的数量：

蒙特卡洛概率算法计算圆周率:输入点的数量：9887766PI=3.141522968889029输入圆半径5The area is78.53807422222573The circle is31.415229688890292