一、效果：
image.png
二、操作步骤：
1.输入框输入汉诺塔的层数
2.点击start
3.生成汉诺塔
4.chrome F12 点击执行代码块（如下图），可看到汉诺塔每一块的移动过程
image.png
三、分析
1.获取输入值
// 获取输入值
function getNumber() {
return document.getElementById('number').value;
}
2.生成随机颜色
// 生成随机颜色
function randomColor() {
var colors = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'];
var color = '#';
for (var i = 0; i < 6; i++) {
color += colors[Math.floor(Math.random() * 16)]
}
return color;
}
3.渲染汉诺塔
// 渲染汉诺塔初始化
function init() {
// 生成三个柱子
var number = getNumber();
var A = document.getElementById('A');
var B = document.getElementById('B');
var C = document.getElementById('C');
// 清空柱子C
C.innerHTML = "";
var htmlA = "";
// 渲染柱子A
for (var i = 0; i < number; i++) {
htmlA += "<div style='width:" + 100 * ((i + 1) / number) + "%;background:" + randomColor() + "'></div>";
}
A.innerHTML = htmlA;
hano(number, A, B, C);
}
4.汉诺塔递归
// 执行汉诺塔递归函数
function hano(n, A, B, C) {
if (n == 1) {
//汉诺塔移动代码
moveHano(A,C);
} else {
hano(n - 1, A, C, B);
hano(1, A, B, C);
hano(n - 1, B, A, C);
}
}
5.汉诺塔移动
function moveHano(A, C) {
// objA 内部第一个元素 objA.childNodes[0]
debugger;
if(C.childNodes[0]){
C.insertBefore(A.childNodes[0],C.childNodes[0]);
}else{
C.appendChild(A.childNodes[0]);
}
}
四、完整代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>hano</title>
<style>
html,
body {
margin: 0;
padding: 0;
height: 100%;
}
.header > #number{
display: inline-block;
width: 80%;
height: 28px;
box-sizing: border-box;
position: absolute;
left: 0;
}
.header > #sure{
display: inline-block;
width: 20%;
height: 28px;
box-sizing: border-box;
position: absolute;
right: 0;
}
#contain{
width: 100%;
background: skyblue;
padding: 10px;
text-align: center;
position: absolute;
top: 28px;
user-select: none;
}
.item{
display: inline-block;
box-sizing: border-box;
background: #ffffff;
border: 1px solid #ffffff;
border-radius: 10px;
width: 33%;
}
.item p{
font-size: 20px;
font-weight: bolder;
border-top: 1px solid #ffffff;
border-bottom: 1px solid #ffffff;
}
.item > .area div{
margin: 0 auto;
height: 20px;
}
</style>
</head>
<body>
<div class="header">
<input id="number" type="text" placeholder="please input number...">
<button id="sure">start</button>
</div>
<div id="contain">
<p>there will be showing result for you.</p>
<div>
<div class="item">
<p>A</p>
<div class="area" id="A">
</div>
</div>
<div class="item">
<p>B</p>
<div class="area" id="B">
</div>
</div>
<div class="item">
<p>C</p>
<div class="area" id="C">
</div>
</div>
</div>
</div>
<script>
// 点击开始按钮事件
var sure = document.getElementById('sure');
sure.addEventListener('click', function () {
init();
})
// 获取输入值
function getNumber() {
return document.getElementById('number').value;
}
// 渲染汉诺塔初始化
function init() {
// 生成三个柱子
var number = getNumber();
var A = document.getElementById('A');
var B = document.getElementById('B');
var C = document.getElementById('C');
// 清空柱子C
C.innerHTML = "";
var htmlA = "";
// 渲染柱子A
for (var i = 0; i < number; i++) {
htmlA += "<div style='width:" + 100 * ((i + 1) / number) + "%;background:" + randomColor() + "'></div>";
}
A.innerHTML = htmlA;
hano(number, A, B, C);
}
// 生成随机颜色
function randomColor() {
var colors = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'];
var color = '#';
for (var i = 0; i < 6; i++) {
color += colors[Math.floor(Math.random() * 16)]
}
return color;
}
// 执行汉诺塔
function hano(n, A, B, C) {
if (n == 1) {
//汉诺塔移动代码
moveHano(A,C);
} else {
hano(n - 1, A, C, B);
hano(1, A, B, C);
hano(n - 1, B, A, C);
}
}
function moveHano(A, C) {
// objA 内部第一个元素 objA.childNodes[0]
debugger;
if(C.childNodes[0]){
C.insertBefore(A.childNodes[0],C.childNodes[0]);
}else{
C.appendChild(A.childNodes[0]);
}
}
</script>
</body>
</html>
