寻找最小的传感器进行覆盖问题（求大神帮忙指正）

[不許人間見白頭]

package package1;
//import java.math.*;


public class Doitpoint {
	static char  map[][]=new char[100][100];
	static point pointlin[]=new point[300];
	
	public static void make_point() {
		for (int i = 0; i < pointlin.length; i++) {
			pointlin[i] = new point();
		}
	}
	//判断是否传感器休眠内部循环
	public static void testpointin(point point1, point point2) {
		int _x = Math.abs(point1.point_x - point2.point_x);
		int _y = Math.abs(point1.point_y - point2.point_y);
		double doxy= Math.sqrt(_x*_x+_y*_y);
		if(doxy<8)
			point1.alive = 'b';
	}
	
	
	
	//判断是否传感器休眠外部循环
	public static void testpoint(point [] pointline) {
		//外循环要测试的点
		for (int i = 0; i < pointline.length; i++) {
			
			//内循环寻找探针PRB_RPY
			if(pointline[i].alive =='a')
			{
				for(int j=i+1;j<pointline.length;j++)
				{
					if(pointline[j].alive =='a')
					{
						testpointin(pointline[i], pointline[j]);
					}
					if (pointline[i].alive =='b')
						break;
					
			
				}
			}
		}
	}
	
	//绘制传感器覆盖的图像
	public static void DrawingPoint(point[] pointlin) {
		
		for (int i = 0; i < pointlin.length; i++) {
			if(pointlin[i].alive =='a')
				//覆盖的计算
				NewDraw(pointlin[i].point_x,pointlin[i].point_y);
		}
		System.out.println((map.toString()));
		
	}
	//刷新覆盖数组
	public static void NewDraw(int x ,int y)
	{
		map[x][y]='*';
		int x1=x-8;
		if (x1<0) {
			x1=0;
		}
		
		int x2=x+8;
		if (x2>100) {
			x2=100;
		}
		
		int y1=y-8;
		if (y1<0) {
			y1=0;
		}
		
		int y2=y+8;
		if(y2>100){
			y2=100;
		}
		for (int charx = x1; x<=x2 ; x++) {
			for (int chary =y1; chary <= y2; chary++) {
				if (map[charx][chary] !='*') 
				{
					map[charx][chary] = '0';
				}
			}
		}	
		
	}
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		//point  pointlin[]=new point[300];
		make_point();
		DrawingPoint(pointlin);
		
		
	}

}
[code]package package1;
//import java.math.*;

package package1;

class point{
	public int point_x;
	public int point_y;
	public char alive = 'a' ;
//使用中发现用不着了 	public int PRB_RPY=0;
	//构造探针并且对其随机覆盖位置
	public point() {
		// TODO Auto-generated constructor stub
		point_x=(int)(Math.random()*100);
		point_y=(int)(Math.random()*100);
	}
}


public class Doitpoint {
	static char  map[][]=new char[100][100];
	static point pointlin[]=new point[300];
	
	public static void make_point() {
		for (int i = 0; i < pointlin.length; i++) {
			pointlin[i] = new point();
		}
	}
	//判断是否传感器休眠内部循环
	public static void testpointin(point point1, point point2) {
		int _x = Math.abs(point1.point_x - point2.point_x);
		int _y = Math.abs(point1.point_y - point2.point_y);
		double doxy= Math.sqrt(_x*_x+_y*_y);
		if(doxy<8)
			point1.alive = 'b';
	}
	
	
	
	//判断是否传感器休眠外部循环
	public static void testpoint(point [] pointline) {
		//外循环要测试的点
		for (int i = 0; i < pointline.length; i++) {
			
			//内循环寻找探针PRB_RPY
			if(pointline[i].alive =='a')
			{
				for(int j=i+1;j<pointline.length;j++)
				{
					if(pointline[j].alive =='a')
					{
						testpointin(pointline[i], pointline[j]);
					}
					if (pointline[i].alive =='b')
						break;
					
			
				}
			}
		}
	}
	
	//绘制传感器覆盖的图像
	public static void DrawingPoint(point[] pointlin) {
		
		for (int i = 0; i < pointlin.length; i++) {
			if(pointlin[i].alive =='a')
				//覆盖的计算
				NewDraw(pointlin[i].point_x,pointlin[i].point_y);
		}
		System.out.println((map.toString()));
		
	}
	//刷新覆盖数组
	public static void NewDraw(int x ,int y)
	{
		map[x][y]='*';
		int x1=x-8;
		if (x1<0) {
			x1=0;
		}
		
		int x2=x+8;
		if (x2>100) {
			x2=100;
		}
		
		int y1=y-8;
		if (y1<0) {
			y1=0;
		}
		
		int y2=y+8;
		if(y2>100){
			y2=100;
		}
		for (int charx = x1; x<=x2 ; x++) {
			for (int chary =y1; chary <= y2; chary++) {
				if (map[charx][chary] !='*') 
				{
					map[charx][chary] = '0';
				}
			}
		}	
		
	}
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		//point  pointlin[]=new point[300];
		make_point();
		DrawingPoint(pointlin);
		
		
	}

}

求大神指教！！谢谢了！！