258 lines
13 KiB
HTML
258 lines
13 KiB
HTML
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<!DOCTYPE html>
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<html lang="zh-Hans">
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<head>
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<meta charset="UTF-8">
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<meta name="viewport" content="width=device-width, initial-scale=1.0">
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<title>035. LRU 缓存 – 图解</title>
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<link rel="stylesheet" href="../shared/style.css">
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<style>
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/* page-specific overrides */
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.vis-area { min-height: 120px; padding: 16px 0; }
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.code-section { margin-top: 16px; }
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</style>
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</head>
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<body>
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<div class="container">
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<h1>🟡 035. LRU 缓存 <span class="badge medium">中等</span></h1>
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<p class="subtitle">分类：链表 ｜ LeetCode Hot 100</p>
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<!-- 控制面板 -->
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<div class="controls" id="controls">
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<label for="inputArea">输入：</label>
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<input type="text" id="inputArea" placeholder="默认示例，可自定义">
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<button id="applyBtn" class="primary">生成图解</button>
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<select id="exampleSelect"></select>
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<span style="flex:1"></span>
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<button id="prevBtn">◀ 上一步</button>
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<button id="nextBtn">下一步 ▶</button>
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<button id="jumpBtn">⏭ 跳到结果</button>
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<button id="autoBtn">自动播放</button>
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<button id="resetBtn">重置</button>
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</div>
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<!-- 步骤流水线 -->
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<div class="pipeline" id="pipeline"></div>
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<!-- 提示条 -->
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<div class="hint info" id="hintBox">
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<span id="stepInfo"></span><br>
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<span id="hintText"></span>
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</div>
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<!-- 可视化面板 -->
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<div class="panels">
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<div class="panel" id="mainPanel">
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<h3>📊 可视化</h3>
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<div class="vis-area" id="vizArea">点击「生成图解」开始</div>
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</div>
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<div class="panel-grid">
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<div class="panel" id="detailPanel">
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<h3>📝 当前步骤详情</h3>
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<div id="detailContent">等待开始...</div>
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</div>
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<div class="panel" id="resultPanel">
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<h3>✅ 结果</h3>
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<div id="resultContent">等待完成...</div>
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</div>
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</div>
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</div>
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<!-- 代码 -->
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<div class="panel code-section">
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<h3>💻 参考代码（Python）</h3>
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<div id="codeArea"></div>
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</div>
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<footer>Powered by QwenPaw · 图解算法 · LeetCode Hot 100</footer>
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</div>
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<script src="../shared/algo-viz.js"></script>
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<script>
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"use strict";
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(function() {
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// ========== Algorithm Logic ==========
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function llViz(nodes, opts) {
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opts = opts || {};
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var highs = opts.highs || {};
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var ptrs = opts.ptrs || {};
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var cycle = opts.cycle != null ? opts.cycle : -1;
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var label = opts.label || '';
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var showNull = opts.showNull !== false;
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var html = '';
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if (label) html += '<div style="font-size:13px;font-weight:600;color:var(--text-secondary);margin-bottom:4px;">' + label + '</div>';
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html += '<div style="display:flex;flex-wrap:wrap;align-items:center;gap:4px;padding:4px 0;">';
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for (var i = 0; i < nodes.length; i++) {
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var cls = highs[i] || '';
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html += '<div style="position:relative;display:inline-flex;flex-direction:column;align-items:center;">';
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html += '<div class="ll-node ' + cls + '">';
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html += '<span class="val">' + nodes[i] + '</span>';
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if (i === cycle) {
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html += '<span class="arrow" style="color:var(--red);font-weight:bold;">↩</span>';
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} else if (i < nodes.length - 1) {
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html += '<span class="arrow">→</span>';
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} else if (showNull && i === nodes.length - 1) {
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html += '<span class="arrow" style="color:var(--text-muted);">∅</span>';
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}
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html += '</div>';
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var plabels = [];
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var pkeys = Object.keys(ptrs);
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for (var pi = 0; pi < pkeys.length; pi++) {
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if (ptrs[pkeys[pi]] === i) plabels.push(pkeys[pi]);
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}
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if (plabels.length) {
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html += '<div style="font-size:10px;font-weight:700;color:var(--blue);margin-top:2px;white-space:nowrap;">' + plabels.join(',') + '</div>';
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}
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html += '</div>';
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}
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html += '</div>';
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return html;
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}
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function setPipeline(stages, current) {
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$('pipeline').innerHTML = stages.map(function(st) {
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var parts = st.split('\u2192');
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return '<span class="pipe-step ' + (current===parts[0]?'active':'') + '">' + parts[1] + '</span>';
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}).join('<i>\u2192</i>');
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}
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var examples = [
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{ops:['LRUCache(2)','put(1,1)','put(2,2)','get(1)','put(3,3)','get(2)','put(4,4)','get(1)','get(3)','get(4)'], label:'示例1: capacity=2'},
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{ops:['LRUCache(3)','put(1,1)','put(2,2)','put(3,3)','get(1)','put(4,4)','get(2)'], label:'示例2: capacity=3'},
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];
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var steps, stepCtrl;
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function buildSteps(ex) {
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steps = [];
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var cap = 2;
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var ops = ex.ops;
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var capMatch = ops[0].match(/LRUCache\((\d+)\)/);
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if (capMatch) cap = parseInt(capMatch[1]);
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// DLL: head <-> ... <-> tail (head=most recent, tail=least recent)
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var dll = []; // [{key, val}]
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var map = {}; // key -> index in dll
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var capacity = cap;
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steps.push({stage:'init', msg:'LRU 缓存初始化，capacity=' + cap + '。双向链表（头=最近，尾=最久）+ 哈希表', dll:[], map:{}, capacity:capacity, op:ops[0]});
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for (var opIdx = 1; opIdx < ops.length; opIdx++) {
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var op = ops[opIdx];
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var getMatch = op.match(/get\((\d+)\)/);
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var putMatch = op.match(/put\((\d+),(\d+)\)/);
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if (getMatch) {
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var key = getMatch[1];
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if (key in map) {
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// hit: move to front
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var idx = map[key];
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var node = dll[idx];
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dll.splice(idx, 1);
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dll.unshift(node);
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// rebuild map
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map = {};
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for (var mi = 0; mi < dll.length; mi++) map[dll[mi].key] = mi;
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steps.push({stage:'hit', msg:'get('+key+') 命中！返回 '+node.val+'，移到链表头部', dll:JSON.parse(JSON.stringify(dll)), map:JSON.parse(JSON.stringify(map)), capacity:capacity, op:op, hitVal:node.val});
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} else {
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steps.push({stage:'miss', msg:'get('+key+') 未命中，返回 -1', dll:JSON.parse(JSON.stringify(dll)), map:JSON.parse(JSON.stringify(map)), capacity:capacity, op:op, hitVal:-1});
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}
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} else if (putMatch) {
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var key = putMatch[1];
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var val = putMatch[2];
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if (key in map) {
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// update: move to front
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var idx = map[key];
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dll[idx].val = val;
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var node = dll[idx];
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dll.splice(idx, 1);
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dll.unshift(node);
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map = {};
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for (var mi = 0; mi < dll.length; mi++) map[dll[mi].key] = mi;
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steps.push({stage:'update', msg:'put('+key+','+val+') 更新已有key，移到头部', dll:JSON.parse(JSON.stringify(dll)), map:JSON.parse(JSON.stringify(map)), capacity:capacity, op:op});
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} else {
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if (dll.length >= capacity) {
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// evict LRU (tail)
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var evicted = dll.pop();
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delete map[evicted.key];
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steps.push({stage:'evict', msg:'put('+key+','+val+') 容量已满，淘汰尾部 key='+evicted.key+' (val='+evicted.val+')', dll:JSON.parse(JSON.stringify(dll)), map:JSON.parse(JSON.stringify(map)), capacity:capacity, op:op, evicted:evicted.key});
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}
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dll.unshift({key:key, val:val});
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map = {};
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for (var mi = 0; mi < dll.length; mi++) map[dll[mi].key] = mi;
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steps.push({stage:'insert', msg:'put('+key+','+val+') 插入到头部', dll:JSON.parse(JSON.stringify(dll)), map:JSON.parse(JSON.stringify(map)), capacity:capacity, op:op});
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}
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}
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}
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steps.push({stage:'done', msg:'操作完毕', dll:JSON.parse(JSON.stringify(dll)), map:JSON.parse(JSON.stringify(map)), capacity:capacity});
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}
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function renderDLL(dll) {
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if (!dll || dll.length === 0) return '<div style="color:var(--text-muted);font-style:italic;padding:8px 0;">[空]</div>';
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var html = '<div style="display:flex;flex-wrap:wrap;align-items:center;gap:2px;padding:4px 0;">';
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html += '<div style="padding:2px 6px;font-size:11px;font-weight:700;color:var(--green);">HEAD</div>';
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for (var i = 0; i < dll.length; i++) {
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var n = dll[i];
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var isHead = (i === 0);
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var isTail = (i === dll.length - 1);
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var bg = isHead ? 'var(--green-light)' : isTail ? 'var(--orange-light)' : 'var(--blue-light)';
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var border = isHead ? 'var(--green)' : isTail ? 'var(--orange)' : 'var(--blue)';
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html += '<div style="border:2px solid '+border+';border-radius:8px;overflow:hidden;display:inline-flex;">';
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html += '<div style="min-width:32px;height:32px;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:12px;padding:0 6px;background:'+bg+';color:var(--text);">k'+n.key+'</div>';
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html += '<div style="min-width:24px;height:32px;display:flex;align-items:center;justify-content:center;font-size:12px;padding:0 4px;background:#f8fafc;border-left:1px solid var(--border);">v'+n.val+'</div>';
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html += '</div>';
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if (i < dll.length - 1) html += '<span style="color:var(--text-muted);">↔</span>';
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}
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html += '<div style="padding:2px 6px;font-size:11px;font-weight:700;color:var(--orange);">TAIL</div>';
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html += '</div>';
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return html;
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}
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function render(step) {
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var s = steps[step];
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var viz = '<div style="margin-bottom:6px;font-size:14px;font-weight:600;color:var(--text-secondary);">当前操作：<code>' + s.op + '</code></div>';
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viz += renderDLL(s.dll);
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// Show map
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if (s.map && Object.keys(s.map).length > 0) {
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viz += '<div style="margin-top:8px;font-size:13px;"><b>HashMap：</b>';
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Object.keys(s.map).forEach(function(k) {
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viz += '<code>'+k+'→idx'+s.map[k]+'</code> ';
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});
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viz += '</div>';
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}
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viz += '<div style="margin-top:6px;font-size:12px;color:var(--text-muted);">容量: ' + s.dll.length + '/' + s.capacity + '</div>';
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$('vizArea').innerHTML = viz;
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$('detailContent').innerHTML = '<div class="calc-block">' + s.msg + '</div>';
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if (s.hitVal !== undefined) {
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$('detailContent').innerHTML += '<div class="current-answer">返回值：<b>' + s.hitVal + '</b></div>';
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}
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if (s.stage === 'done') {
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$('resultContent').innerHTML = '<div class="final-answer">缓存最终状态：[' + s.dll.map(function(n){return n.key+':'+n.val;}).join(', ') + ']</div>';
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}
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$('hintText').textContent = s.msg;
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setPipeline(['init\u2192初始化','hit\u2192命中','miss\u2192未命中','update\u2192更新','evict\u2192淘汰','insert\u2192插入','done\u2192完成'], s.stage);
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}
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function init() {
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var sel = $('exampleSelect');
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examples.forEach(function(e,i){ sel.innerHTML += '<option value="'+i+'">'+e.label+'</option>'; });
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$('inputArea').value = 'LRUCache(2) put(1,1) put(2,2) get(1) put(3,3) get(2)';
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buildSteps(examples[0]);
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stepCtrl = new StepController({onStep:render});
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stepCtrl.setSteps(steps.map(function(_,i){return i;}));
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$('stepInfo').textContent = '步骤 1 / ' + steps.length;
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stepCtrl.onStep = function(idx){ render(idx); $('stepInfo').textContent = '步骤 '+(idx+1)+' / '+steps.length; };
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$('applyBtn').onclick = function(){ buildSteps(examples[parseInt($('exampleSelect').value)]); stepCtrl.setSteps(steps.map(function(_,i){return i;})); render(0); };
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$('exampleSelect').onchange = function(){ buildSteps(examples[parseInt($('exampleSelect').value)]); stepCtrl.setSteps(steps.map(function(_,i){return i;})); render(0); };
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$('prevBtn').onclick = function(){ stepCtrl.prev(); };
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$('nextBtn').onclick = function(){ stepCtrl.next(); };
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$('jumpBtn').onclick = function(){ stepCtrl.jumpToEnd(); };
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$('autoBtn').onclick = function(){ var on=stepCtrl.toggleAuto(); $('autoBtn').textContent=on?'暂停':'自动播放'; };
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$('resetBtn').onclick = function(){ stepCtrl.reset(); $('autoBtn').textContent='自动播放'; };
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}
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init();
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$('codeArea').innerHTML = renderCode('class LRUCache:\n def __init__(self, capacity):\n self.cap = capacity\n self.cache = {}\n self.head = DLinkedNode()\n self.tail = DLinkedNode()\n self.head.next = self.tail\n self.tail.prev = self.head\n\n def _remove(self, node):\n node.prev.next = node.next\n node.next.prev = node.prev\n\n def _add_to_head(self, node):\n node.prev = self.head\n node.next = self.head.next\n self.head.next.prev = node\n self.head.next = node\n\n def get(self, key):\n if key not in self.cache:\n return -1\n node = self.cache[key]\n self._remove(node)\n self._add_to_head(node)\n return node.val\n\n def put(self, key, value):\n if key in self.cache:\n node = self.cache[key]\n node.val = value\n self._remove(node)\n self._add_to_head(node)\n else:\n if len(self.cache) >= self.cap:\n tail = self.tail.prev\n self._remove(tail)\n del self.cache[tail.key]\n node = DLinkedNode(key, value)\n self.cache[key] = node\n self._add_to_head(node)', {lang:'Python'});
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})();
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</script>
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</body>
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</html>
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