喜羊羊与灰太狼——重现高中生物书中的狼群与羊群的数量变化关系曲线图

半年前把这个小模型做出来了，今天有小小的重构了一下，模型蛮有趣的，以后有空再加入别的控制条件:

以下是代码的具体实现，一共有三个类

Forest.java

package wolf_sheep;import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.ArrayList;
import java.util.List;public class Forset extends Frame{public static final int ROWS=105;public static final int COLS=270;public static final int BLOCK_SIZE=5;private Image offScreenImage;public static List<Integer> sheepcount = null;public static List<Integer> wolfcount = null;public static void main(String[] args) {new Forset().launch();}public void launch(){setBounds(10, 10, BLOCK_SIZE*COLS, BLOCK_SIZE*(ROWS+40));addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e){System.exit(0);}});sheepcount = new ArrayList<>() ;wolfcount = new ArrayList<>();Sheep.sheeps.add(new Sheep());Wolf.wolfs.add(new Wolf());setVisible(true);run();}private void run() {while(true){repaint();          try {/*** 设置狼与羊的移动频率 ；*/Thread.sleep(10);} catch (InterruptedException e) {e.printStackTrace();}}}@Overridepublic void paint(Graphics g) {g.setColor(Color.GRAY);g.fillRect(0, 0, BLOCK_SIZE*COLS, BLOCK_SIZE*(ROWS+40));g.setColor(Color.BLACK);for (int x=1;x<COLS;x++){g.drawLine(BLOCK_SIZE*x, 0, BLOCK_SIZE*x, BLOCK_SIZE*ROWS);}for (int x=1;x<ROWS;x++){g.drawLine(0, BLOCK_SIZE*x, BLOCK_SIZE*COLS, BLOCK_SIZE*x);}for(int x=0;x<Sheep.sheeps.size();x++){/*** 画出羊群的移动路径；*/Sheep.sheeps.get(x).draw(g);Sheep.sheeps.get(x).run();Sheep.sheeps.get(x).addNewSheep();Sheep.sheeps.get(x).checkDeach();/*** 下面的for循环表示两羊相遇死一个；*//*for(int y=x+1;y<Sheep.sheeps.size();y++){if(Sheep.sheeps.get(x).getRect().intersects(Sheep.sheeps.get(y).getRect())){Sheep.sheeps.remove(Sheep.sheeps.get(x));}}*/}for(int x=0;x<Wolf.wolfs.size();x++){/*** 画出狼群的移动路径；*/Wolf.wolfs.get(x).draw(g);Wolf.wolfs.get(x).run();/*** 狼碰到羊后，狼会把羊吃掉，并生一只小狼；*/for(int y=0;y<Sheep.sheeps.size();y++){if(Sheep.sheeps.get(y).getRect().intersects(Wolf.wolfs.get(x).getRect())){Wolf.wolfs.add(new Wolf());Sheep.sheeps.remove(Sheep.sheeps.get(y));}}/*** 下面的for循环表示两狼相遇死一个；* 把它注释掉后生态系统会趋向于奔溃，有兴趣可以试一试；*/for(int y=x+1;y<Wolf.wolfs.size();y++){if(Wolf.wolfs.get(x).getRect().intersects(Wolf.wolfs.get(y).getRect())){Wolf.wolfs.remove(Wolf.wolfs.remove(x));}}if(x>0){Wolf.wolfs.get(x).checkDeach();}}sheepcount.add(Sheep.sheeps.size());wolfcount.add(Wolf.wolfs.size());int b = 20;for(int x=1;x<sheepcount.size();x++){g.setColor(Color.RED);g.drawLine(b/3,700-sheepcount.get(x-1)/5, b++/3, 700-sheepcount.get(x)/5);}b = 20;for(int x=1;x<wolfcount.size();x++){g.setColor(Color.BLACK);g.drawLine(b/3,700-wolfcount.get(x-1)/5, b++/3, 700-wolfcount.get(x)/5);}}@Overridepublic void update(Graphics g) {offScreenImage = this.createImage(COLS * BLOCK_SIZE, (ROWS+40) * BLOCK_SIZE);Graphics gOff = offScreenImage.getGraphics();paint(gOff);g.drawImage(offScreenImage, 0, 0, null);}
}

Sheep.java

package wolf_sheep;import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;public class Sheep{private int row;private int col;private int foot;private int old ;public static List<Sheep> sheeps = new ArrayList<>();private  static Random rd = new Random();public Sheep(){row = rd.nextInt(Forset.ROWS-2)+2;col = rd.nextInt(Forset.COLS);}public void draw (Graphics g){g.setColor(Color.PINK);g.fillOval(Forset.BLOCK_SIZE * col, Forset.BLOCK_SIZE * row, Forset.BLOCK_SIZE, Forset.BLOCK_SIZE);}public Rectangle getRect(){return new Rectangle(Forset.BLOCK_SIZE * col, Forset.BLOCK_SIZE * row, Forset.BLOCK_SIZE, Forset.BLOCK_SIZE);}public static int giveBirth(){int day =rd.nextInt(15)-5;if(day>5){return day;}else{return 10;}}public void addNewSheep(){  if(foot>=Sheep.giveBirth()){foot=0;sheeps.add(new Sheep());}}public void checkDeach(){if(this.old>15){sheeps.remove(this);}}public void run() {switch (rd.nextInt(4)){case 1:if(row>5){row = row-1;}break;case 2:if(col<Forset.COLS-5){col = col+1;}break;case 3:if(row<Forset.ROWS-5){row = row+1;}break;case 0:if(col>5){col = col-1;}break;}foot ++;old ++;}
}

Wolf.java

package wolf_sheep;import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;public class Wolf {int row;int col;int old ;public static List<Wolf> wolfs = new ArrayList<>();private  static Random rd = new Random();public Wolf(){row = rd.nextInt(Forset.ROWS-2)+2;col = rd.nextInt(Forset.COLS);}public void draw (Graphics g){g.setColor(Color.BLACK);g.fillRect(Forset.BLOCK_SIZE * col, Forset.BLOCK_SIZE * row, Forset.BLOCK_SIZE*2, Forset.BLOCK_SIZE*2);}public Rectangle getRect(){return new Rectangle(Forset.BLOCK_SIZE * col, Forset.BLOCK_SIZE * row, Forset.BLOCK_SIZE*2, Forset.BLOCK_SIZE*2);}public void checkDeach(){if(this.old>50){wolfs.remove(this);}}public void run() {switch (rd.nextInt(4)){case 1:if(row>5){row = row-1;}break;case 2:if(col<Forset.COLS-5){col = col+1;}break;case 3:if(row<Forset.ROWS-5){row = row+1;}break;case 0:if(col>5){col = col-1;}break;}old ++;}
}

• 下面是演示的图片