画二叉树 java实现

来源：互联网发布：故宫淘宝h5 编辑：程序博客网时间：2024/05/01 19:06

最近无聊，写了一个画二叉树的程序。

[java]view plaincopyprint?

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.PriorityQueue;
import java.util.Queue;
import java.util.Stack;
import javax.imageio.ImageIO;
publicclass TreeDrawer {
int totalLevel = 0;
int leftpadding = Integer.MAX_VALUE;
publicvoid printTree(TreeNode root, String name) throws IOException{
totalLevel = getTotalLevel(root) - 1;
BufferedImage bi = new BufferedImage(1366, 768, BufferedImage.TYPE_INT_BGR);
Graphics2D g = bi.createGraphics();
g.setBackground(Color.cyan);
g.setColor(Color.blue);
ArrayList q = new ArrayList();
q.add(root);
BFSAndPaint(g, q, 0, false);
bi = new BufferedImage(1366, 768, BufferedImage.TYPE_INT_BGR);
g = bi.createGraphics();
BFSAndPaint(g, q, 0, true);
ImageIO.write(bi, "png", new File(name + ".png"));
this.leftpadding = Integer.MAX_VALUE;
}
publicvoid BFSAndPaint(Graphics2D g, ArrayList l, int level, boolean repaint){
ArrayList buff = new ArrayList();
for(int i = 0; i < lsizeispan>
TreeNode current = l.get(i);
GraphicNode gnode = null;
if(null != current){
gnode = new GraphicNode(level, i, totalLevel);
int gnodeX = gnode.getPoint(repaint).x;
int gnodeY = gnode.getPoint(repaint).y;
g.drawString(current.node + "", gnodeX, gnodeY);
if(gnodeX < leftpaddingrepaintspan>
leftpadding = gnodeX;
}
if(null != current.left){
int leftIndex = i * 2;
GraphicNode gnode_left = new GraphicNode(level + 1, leftIndex, totalLevel);
g.drawLine(gnodeX + 5, gnodeY, gnode_left.getPoint(repaint).x + 5, gnode_left.getPoint(repaint).y - 10);
}
buff.add(current.left);
if(null != current.right){
int rightIndex = i * 2 + 1;
GraphicNode gnode_right = new GraphicNode(level + 1, rightIndex, totalLevel);
g.drawLine(gnodeX + 5, gnodeY, gnode_right.getPoint(repaint).x + 5, gnode_right.getPoint(repaint).y - 10);
}
buff.add(current.right);
}else{
buff.add(null);
buff.add(null);
}
}
if(isBuffEmpty(buff)){
return;
}else{
BFSAndPaint(g, buff, level + 1, repaint);
}
}
publicstaticvoid main(String args []) throws IOException{
TreeDrawer drawer = new TreeDrawer();
drawer.run();
}
privatevoid run() throws IOException{
TreeNode node = new TreeNode((int)(Math.random() * 100));
this.createBT(node, 0);
this.printTree(node, "test");
}
privatevoid createBT(TreeNode node, int n){
if(n < 5){
return;
}
boolean hasLeft = Math.random() < 0.2 ? true : false;
if(hasLeft){
node.left = new TreeNode((int)(Math.random() * 100));
createBT(node.left, n + 1);
}
boolean hasRight = Math.random() < 0.1 ? true : false;
if(hasRight){
node.right = new TreeNode((int)(Math.random() * 100));
createBT(node.right, n + 1);
}
}
privateboolean isBuffEmpty(List list){
boolean ret = true;
for(TreeNode node : list){
if(null != node)
ret = false;
}
return ret;
}
privateint getTotalLevel(TreeNode node){
if(null == node){
return0;
}
return Math.max(getTotalLevel(node.left), getTotalLevel(node.right)) + 1;
}
privateclass GraphicNode{
private Point p;
privateint level;
privateint index;
publicstaticfinalint LOWEST_PADDING = 20;// padding of lowest level. first level is 0
publicstaticfinalint LEVEL_PADDING = 30;//padding between levels
privateint totalLevel;
public GraphicNode(int level, int index, int totalLevel){ //total level is equal to lowest level
this.level = level;
this.index = index;
this.totalLevel = totalLevel;
this.p = computeP(this.level, this.index);
}
private Point computeP(int level, int index) {
int x = 0;
for(int i = this.totalLevel; i <level; i--){
x += getLevelPadding(i) / 2;
}
x += getLevelPadding(level) * index;
int y = LEVEL_PADDING * (level + 1);
returnnew Point(x, y);
}
public Point getPoint(boolean repaint){
if(repaint){
returnnew Point(p.x - leftpadding, p.y);
}
return p;
}
privateint getLevelPadding(int level){
return (int) (LOWEST_PADDING * Math.pow(2, this.totalLevel - level));
}
}
privateclass Point{
int x;
int y;
public Point(int x, int y){
this.x = x;
this.y = y;
}
publicint getX(){
returnthis.x;
}
publicint getY(){
returnthis.y;
}
}
privateclass TreeNode{
int node;
TreeNode left;
TreeNode right;
public TreeNode(int n){
node = n;
left = null;
right = null;
}
}
}

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