查询Math类的方法,打印出如右所示的近似圆,只要给定不同半径,圆的大小就会随之发生改变。

public class JinSiYuan {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入○的半径：");
        int r = scanner.nextInt();//半径
        JinSiYuan jsy = new JinSiYuan();
        jsy.PrintCricle(r);
    }
    public void PrintCricle(int r){
        double R = 2 * r;//直径
        for (int i = 0;  i <= R; i += 2){ //i代表每一行
            double y = Math.round(Math.sqrt(r * r - Math.pow(r-i,2))); // 圆上点到竖着半径的距离
            double x = r-y;//圆上点到外切正方形边的距离

            //打印正方形左边边到圆上点的空白部分
            for (int j = 0; j < x; j++){
                System.out.print(" ");
            }
            //打印左边的圆上点
            System.out.print("*");
            //打印出中间空白部分
            for (int j = 0; j < 2 * y; j++){
                System.out.print(" ");
            }
            //打印出右边圆上点，直接换行
            System.out.println("*");
        }
    }
}