【Java_Base】Math类+循环实现星星打印近似圆

 1 import java.lang.Math;
 2 public class Print_Circle {
 3     public static void main(String[] args) {
 4         paint(10); //半径10
 5     }
 6     public static void paint(int r) {
 7      //假定圆心在坐标(r,r);
 8         int y = r * 2; //y的坐标开始
 9         int x = 0;
10         int c = 0; //中间空格数量
11         int z = 2; //每行递减量
12         for (int j = r * 2; j >= 0; j=j-z) {
13             x = getX(r, y);
14             System.out.print(getSpace(x) + "*");
15             c = (r-x)*2;
16             System.out.println(getSpace(c) + "*");
17             y-=z;
18         }
19     }
20     public static int getX(int r, int y) {
21         //解圆标准方程的
22         int x = y - r;       
23         double t = Math.sqrt((r * r) - (x * x));
24         return (int) Math.round(r-t);
25     }
26     public static String getSpace(int i) {
27         String s = "";
28         for (int j = 0; j < i; j++) {
29             s += " ";
30         }
31         return s;
32     }
33 }