java 打印 空心菱形

package important;

public class PrintHollowDiamond {
public static String p(int x, int y, int center) {
//当x、y轴大于对称轴时，对cneter取模
if (x > center)
//			x = 2 * center - x;
x = x % center;
if (y > center)
//			y = 2 * center - y;
y = y % center;

//如果x+y等于对称轴，则返回"*"
if (x + y == center)
return "*";
return "-";
}
public static void main(String[] args) {
int line = 3;
int n = 2 * line - 1; //构建一个n行*n行的坐标系
int center = line - 1; //x轴和y轴的对称轴
/**
* center在这里为2，也就是菱形关于x=2和y=2对称
*
*   0 1 2 3 4  x轴
*   - - - - -
* 0|    *
* 1|  *   *
* 2|*       *
* 3|  *   *
* 4|    *
* y
* 轴
*/
for (int x = 0; x < n; x++) {
for (int y = 0; y < n; y++) {
System.out.print(p(x, y, center));
}
System.out.println();
}
}
}