190 lines
7.1 KiB
HTML
190 lines
7.1 KiB
HTML
<!DOCTYPE html>
|
||
<html lang="zh-Hans">
|
||
<head>
|
||
<meta charset="UTF-8">
|
||
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
||
<title>039. 对称二叉树 – 图解</title>
|
||
<link rel="stylesheet" href="../shared/style.css">
|
||
<style>
|
||
/* page-specific overrides */
|
||
.vis-area { min-height: 120px; padding: 16px 0; }
|
||
.code-section { margin-top: 16px; }
|
||
</style>
|
||
</head>
|
||
<body>
|
||
<div class="container">
|
||
<h1>🟢 039. 对称二叉树 <span class="badge easy">简单</span></h1>
|
||
<p class="subtitle">分类：二叉树 ｜ LeetCode Hot 100</p>
|
||
|
||
<!-- 控制面板 -->
|
||
<div class="controls" id="controls">
|
||
<label for="inputArea">输入：</label>
|
||
<input type="text" id="inputArea" placeholder="默认示例，可自定义">
|
||
<button id="applyBtn" class="primary">生成图解</button>
|
||
<select id="exampleSelect"></select>
|
||
<span style="flex:1"></span>
|
||
<button id="prevBtn">◀ 上一步</button>
|
||
<button id="nextBtn">下一步 ▶</button>
|
||
<button id="jumpBtn">⏭ 跳到结果</button>
|
||
<button id="autoBtn">自动播放</button>
|
||
<button id="resetBtn">重置</button>
|
||
</div>
|
||
|
||
<!-- 步骤流水线 -->
|
||
<div class="pipeline" id="pipeline"></div>
|
||
|
||
<!-- 提示条 -->
|
||
<div class="hint info" id="hintBox">
|
||
<span id="stepInfo"></span><br>
|
||
<span id="hintText"></span>
|
||
</div>
|
||
|
||
<!-- 可视化面板 -->
|
||
<div class="panels">
|
||
<div class="panel" id="mainPanel">
|
||
<h3>📊 可视化</h3>
|
||
<div class="vis-area" id="vizArea">点击「生成图解」开始</div>
|
||
</div>
|
||
<div class="panel-grid">
|
||
<div class="panel" id="detailPanel">
|
||
<h3>📝 当前步骤详情</h3>
|
||
<div id="detailContent">等待开始...</div>
|
||
</div>
|
||
<div class="panel" id="resultPanel">
|
||
<h3>✅ 结果</h3>
|
||
<div id="resultContent">等待完成...</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
|
||
<!-- 代码 -->
|
||
<div class="panel code-section">
|
||
<h3>💻 参考代码（Python）</h3>
|
||
<div id="codeArea"></div>
|
||
</div>
|
||
|
||
<footer>Powered by QwenPaw · 图解算法 · LeetCode Hot 100</footer>
|
||
</div>
|
||
|
||
<script src="../shared/algo-viz.js"></script>
|
||
<script>
|
||
"use strict";
|
||
(function() {
|
||
// ========== Algorithm Logic ==========
|
||
|
||
function arrayToTree(arr) {
|
||
if (!arr || arr.length === 0) return null;
|
||
let idCtr = 0;
|
||
const nodes = arr.map(v => v === null ? null : {val: v, left: null, right: null, _id: 'n' + (idCtr++)});
|
||
for (let i = 0; i < nodes.length; i++) {
|
||
if (!nodes[i]) continue;
|
||
const li = 2*i+1, ri = 2*i+2;
|
||
if (li < nodes.length) nodes[i].left = nodes[li];
|
||
if (ri < nodes.length) nodes[i].right = nodes[ri];
|
||
}
|
||
return nodes[0];
|
||
}
|
||
function treeToArray(root) {
|
||
if (!root) return [];
|
||
const res = [], q = [root];
|
||
while (q.length) {
|
||
const n = q.shift();
|
||
if (n === null) { res.push(null); continue; }
|
||
res.push(n.val); q.push(n.left, n.right);
|
||
}
|
||
while (res.length && res[res.length-1] === null) res.pop();
|
||
return res;
|
||
}
|
||
function deepClone(node) {
|
||
if (!node) return null;
|
||
return {val: node.val, _id: node._id, left: deepClone(node.left), right: deepClone(node.right)};
|
||
}
|
||
|
||
const examples = [
|
||
{tree: [1,2,2,3,4,4,3], label: '示例1: 对称 [1,2,2,3,4,4,3]'},
|
||
{tree: [1,2,2,null,3,null,3], label: '示例2: 不对称 [1,2,2,null,3,null,3]'},
|
||
{tree: [1], label: '示例3: [1] 单节点'},
|
||
];
|
||
let root, steps, stepCtrl;
|
||
|
||
function buildSteps(arr) {
|
||
root = arrayToTree(arr);
|
||
steps = [];
|
||
if (!root) { steps.push({stage:'done',hl:{},msg:'空树是对称的',isSym:true}); return; }
|
||
steps.push({stage:'init',hl:{},msg:'递归检查左右子树是否镜像对称',isSym:true});
|
||
|
||
function check(a, b) {
|
||
if (!a && !b) {
|
||
steps.push({stage:'match',hl:{},msg:'两个节点都为空，匹配 ✓',isSym:true});
|
||
return true;
|
||
}
|
||
if (!a || !b) {
|
||
const nonNull = a || b;
|
||
steps.push({stage:'mismatch',hl:{[nonNull._id]:'current'},msg:'一侧为空另一侧不为空，不匹配 ✗',isSym:false});
|
||
return false;
|
||
}
|
||
if (a.val !== b.val) {
|
||
steps.push({stage:'mismatch',hl:{[a._id]:'current',[b._id]:'current'},msg:`节点 ${a.val} ≠ ${b.val}，不匹配 ✗`,isSym:false});
|
||
return false;
|
||
}
|
||
steps.push({stage:'compare',hl:{[a._id]:'active',[b._id]:'active'},msg:`比较 ${a.val} 和 ${b.val}，相等 ✓`,isSym:true});
|
||
const outer = check(a.left, b.right);
|
||
if (!outer) return false;
|
||
return check(a.right, b.left);
|
||
}
|
||
const isSym = check(root.left, root.right);
|
||
steps.push({stage:'done',hl:{},msg:`判断结果：${isSym?'对称 ✓':'不对称 ✗'}`,isSym});
|
||
}
|
||
|
||
function render(step) {
|
||
const s = steps[step];
|
||
let viz = renderBinaryTree(root, {highlights: s.hl});
|
||
$('vizArea').innerHTML = viz;
|
||
$('detailContent').innerHTML = '<div class="calc-block">' + s.msg + '</div>';
|
||
if (s.stage === 'done') {
|
||
$('resultContent').innerHTML = `<div class="final-answer"${!s.isSym?' style="border-color:#f87171;background:#fef2f2;"':''}>是否对称：<b>${s.isSym?'是 ✓':'否 ✗'}</b></div>`;
|
||
}
|
||
$('hintText').textContent = s.msg;
|
||
const stages = ['init→初始化','compare→比较','match→匹配','mismatch→不匹配','done→完成'];
|
||
$('pipeline').innerHTML = stages.map(st => {
|
||
const [k,l] = st.split('→');
|
||
return `<span class="pipe-step ${s.stage===k?'active':''}">${l}</span>`;
|
||
}).join('<i>→</i>');
|
||
}
|
||
|
||
function init() {
|
||
const sel = $('exampleSelect');
|
||
examples.forEach((e,i) => { sel.innerHTML += `<option value="${i}">${e.label}</option>`; });
|
||
$('inputArea').value = '[1,2,2,3,4,4,3]';
|
||
buildSteps(examples[0].tree);
|
||
stepCtrl = new StepController({onStep: render});
|
||
stepCtrl.setSteps(steps.map((_,i)=>i));
|
||
$('stepInfo').textContent = '步骤 1 / ' + steps.length;
|
||
stepCtrl.onStep = (idx) => { render(idx); $('stepInfo').textContent = `步骤 ${idx+1} / ${steps.length}`; };
|
||
$('applyBtn').onclick = () => {
|
||
try { const arr = JSON.parse($('inputArea').value); buildSteps(arr); stepCtrl.setSteps(steps.map((_,i)=>i)); render(0); $('stepInfo').textContent = '步骤 1 / ' + steps.length; }
|
||
catch(e) { alert('请输入合法数组'); }
|
||
};
|
||
$('exampleSelect').onchange = () => {
|
||
const e = examples[parseInt($('exampleSelect').value)];
|
||
$('inputArea').value = JSON.stringify(e.tree);
|
||
buildSteps(e.tree); stepCtrl.setSteps(steps.map((_,i)=>i)); render(0);
|
||
};
|
||
$('prevBtn').onclick = () => stepCtrl.prev();
|
||
$('nextBtn').onclick = () => stepCtrl.next();
|
||
$('jumpBtn').onclick = () => stepCtrl.jumpToEnd();
|
||
$('autoBtn').onclick = () => { const on = stepCtrl.toggleAuto(); $('autoBtn').textContent = on ? '暂停' : '自动播放'; };
|
||
$('resetBtn').onclick = () => { stepCtrl.reset(); $('autoBtn').textContent = '自动播放'; };
|
||
}
|
||
init();
|
||
$('codeArea').innerHTML = renderCode(`def isSymmetric(root):
|
||
def check(a, b):
|
||
if not a and not b: return True
|
||
if not a or not b: return False
|
||
return a.val == b.val and check(a.left, b.right) and check(a.right, b.left)
|
||
return check(root.left, root.right) if root else True`, {lang:'Python'});
|
||
|
||
})();
|
||
</script>
|
||
</body>
|
||
</html> |