1-4 二叉树创建的代码实现
<!-- 稍微改造了一下下，可视化二叉树排序，非常有利于学习和理解哟！-->
<!DOCTYPE html>
<html>
<title>二叉排序树</title>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body >
<canvas id="canvas" width="1366" height="768" ></canvas>
</body>
</html>
<script type="text/javascript">
//二叉算法函数
function BinaryTree(){
//node 节点函数
var Node=function(key){
this.key=key;
this.left=null;
this.right=null;
this.x = 0;//图形绘制坐标
this.y = 0;//图形绘制坐标
};
/**二叉树可视图形描述**/
this.graphical = [];//图形数组
this.lrMove = 100;//左右偏移量
this.udMove = 100;//上下偏移量
/**==================**/
//定义根节点
var root=null;
//插入节点 循环递归函数 左右分插
this.insertNode=function(node,newNode){
if(newNode.key < node.key){
if(node.left===null){
var x = node.x;
var y = node.y;
newNode.x = (x -= this.udMove);
newNode.y = (y += this.lrMove);
node.left=newNode;
}else{
this.insertNode(node.left,newNode);
}
}else{
if(node.right===null){
var x = node.x;
var y = node.y;
newNode.x = (x += this.udMove);
newNode.y = (y += this.lrMove);
node.right=newNode;
}else{
this.insertNode(node.right,newNode);
}
}
};
//入口程序
this.insert=function(key){
var newNode= new Node(key);
if(root===null){
root=newNode;
root.x = 500;
root.y = 100;
this.graphical.push(root);
}else{
this.insertNode(root,newNode);
}
};
var inOrdertraverseNode = function(node,callback){
if(node !== null){
inOrdertraverseNode(node.left,callback);
callback(node.key);
inOrdertraverseNode(node.right,callback);
}
}
this.inOrdertraverse = function(callback){
inOrdertraverseNode(root,callback);
}
}
var nodes=[8,3,10,1,6,14,4,15,12,13];
var binaryTree=new BinaryTree;
for(var i = 0 ; i < nodes.length ; i++){
binaryTree.insert(nodes[i]);
}
var callback = function(key){
console.log(key)
}
binaryTree.inOrdertraverse(callback);
/*=====================================================开始绘制================================*/
var canvas = document.getElementById("canvas");
var context = canvas.getContext('2d'); //获取对应的2D对象(画笔)
function draw(key,x,y){
this.counter = 0;
this.render = function(c){
c.fillStyle = "hsl("+ this.counter +", 100%, 50%)";
c.strokeStyle = '#fff'; //设置笔触的颜色
c.font = "bold 40px '字体','字体','微软雅黑','宋体'"; //设置字体
c.textBaseline = 'hanging'; //在绘制文本时使用的当前文本基线
c.fillText(key ,x ,y);
}
this.update = function(){
this.counter += 5;
}
}
var fontCavaseArr = [];
function init() {
loop();//绘制文字
setInterval(run, 1000/30);
}
function run(x,y){
context.fillStyle = "rgba(0,0,0,0.1)";
context.fillRect(0,0,1366,768); //绘制 1366*768 像素的已填充矩形：
for (i=0; i<fontCavaseArr.length; i++) {
var particle = fontCavaseArr[i];
particle.render(context);
particle.update();
}
gLine();//绘制线条
}
function loop(){
font(binaryTree.graphical[0]);
}
function font(obj){
if(obj.key != null && obj.key != undefined){
var drawFont = new draw(obj.key,obj.x,obj.y);
fontCavaseArr.push(drawFont);
}
if(obj.left != null && obj.left != undefined){
var drawFont = new draw(obj.left.key,obj.left.x,obj.left.y);
fontCavaseArr.push(drawFont);
font(obj.left);
}
if(obj.right != null && obj.right != undefined){
var drawFont = new draw(obj.right.key,obj.right.x,obj.right.y);
fontCavaseArr.push(drawFont);
font(obj.right);
}
}
function gLine(){
line(binaryTree.graphical[0]);
}
function line(obj){
context.lineJoin="round";
context.lineCap="butt";
context.beginPath();
if(obj.left != null && obj.left != undefined){
context.moveTo(obj.x+20,obj.y+20);
context.lineTo(obj.left.x+20,obj.left.y+20);
context.stroke();
context.closePath();
line(obj.left);
}
if(obj.right != null && obj.right != undefined){
context.moveTo(obj.x+20,obj.y+20);
context.lineTo(obj.right.x+20,obj.right.y+20);
context.stroke();
context.closePath();
line(obj.right);
}
}
init();
</script>
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