218 lines
8.9 KiB
HTML
218 lines
8.9 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>062. N 皇后 – 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>🔴 062. N 皇后 <span class="badge hard">困难</span></h1>
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<p class="subtitle">分类：回溯 ｜ 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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const examples = [
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{input: 4, label: '示例1: n=4'},
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{input: 1, label: '示例2: n=1'},
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{input: 6, label: '示例3: n=6'},
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];
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let n, steps, stepCtrl;
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function buildSteps(nn) {
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n = nn; steps = [];
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const result = [];
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const queens = []; // queens[row] = col
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steps.push({stage:'start', msg:`${n}皇后问题：逐行放置，检查列和对角线冲突`, queens:[], row:-1, col:-1, result:[]});
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function isValid(row, col) {
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for (let r = 0; r < queens.length; r++) {
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const c = queens[r];
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if (c === col || r + c === row + col || r - c === row - col) return false;
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}
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return true;
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}
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function backtrack(row) {
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if (row === n) {
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result.push([...queens]);
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const board = queensToBoard(queens);
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steps.push({stage:'collect', msg:`找到解！皇后位置: ${queens.map((c,r)=>`(${r},${c})`).join(' ')}`, queens:[...queens], row, col:-1, result:JSON.parse(JSON.stringify(result))});
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return;
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}
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for (let col = 0; col < n; col++) {
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const valid = isValid(row, col);
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if (valid) {
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steps.push({stage:'try_valid', msg:`行${row} 列${col}: 无冲突 ✓，放置皇后`, queens:[...queens], row, col, result:JSON.parse(JSON.stringify(result))});
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queens.push(col);
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backtrack(row + 1);
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queens.pop();
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steps.push({stage:'undo', msg:`回溯行${row}，移除列${col}皇后`, queens:[...queens], row, col, result:JSON.parse(JSON.stringify(result))});
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} else {
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steps.push({stage:'conflict', msg:`行${row} 列${col}: 冲突 ✗（列/对角线已有皇后）`, queens:[...queens], row, col, result:JSON.parse(JSON.stringify(result))});
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}
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}
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}
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backtrack(0);
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steps.push({stage:'done', msg:`共 ${result.length} 个解`, queens:[], row:-1, col:-1, result:JSON.parse(JSON.stringify(result))});
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}
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function queensToBoard(q) {
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return q.map(c => { let row = '.'.repeat(n); return row.substring(0,c) + 'Q' + row.substring(c+1); });
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}
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function render(step) {
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const s = steps[step];
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const qSet = new Set(s.queens.map((c,r) => r+','+c));
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const tryKey = s.row >= 0 && s.col >= 0 ? s.row+','+s.col : null;
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// Build chess board
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let viz = `<div style="display:inline-grid;grid-template-columns:repeat(${n},42px);gap:2px;padding:8px;border-radius:8px;background:#1e293b;">`;
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for (let r = 0; r < n; r++) {
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for (let c = 0; c < n; c++) {
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const isQueen = s.queens[r] === c;
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const isTry = r === s.row && c === s.col;
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const isConflict = isTry && s.stage === 'conflict';
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let bg = (r+c) % 2 === 0 ? '#f0f9ff' : '#e0f2fe';
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if (isQueen) bg = '#dbeafe';
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if (isConflict) bg = '#fee2e2';
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else if (isTry && s.stage === 'try_valid') bg = '#fef3c7';
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const content = isQueen ? '♛' : '';
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const border = isTry ? `2px solid ${isConflict?'var(--red)':'var(--orange)'}` : isQueen ? '2px solid var(--blue)' : '1px solid #94a3b8';
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viz += `<div style="width:42px;height:42px;display:flex;align-items:center;justify-content:center;background:${bg};border:${border};border-radius:4px;font-size:20px;cursor:default;${isQueen?'color:var(--blue-dark);font-weight:700;':''}">${content}</div>`;
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}
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}
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viz += '</div>';
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// Conflict lines for current try
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if (s.stage === 'conflict' && s.row >= 0) {
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viz += '<div style="margin-top:8px;color:var(--red);font-size:13px;">';
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for (let r=0; r<s.queens.length; r++) {
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const c = s.queens[r];
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if (c === s.col) viz += `列冲突: 行${r}列${c} ↔ 行${s.row}列${s.col} `;
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if (r+c === s.row+s.col) viz += `↗对角线冲突: (${r},${c}) ↔ (${s.row},${s.col}) `;
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if (r-c === s.row-s.col) viz += `↘对角线冲突: (${r},${c}) ↔ (${s.row},${s.col}) `;
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}
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viz += '</div>';
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}
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viz += `<div style="margin-top:8px;"><b>当前放置：</b> ${s.queens.length > 0 ? s.queens.map((c,r)=>`行${r}=列${c}`).join(', ') : '无'}</div>`;
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if (s.result.length > 0) {
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viz += `<div style="margin-top:8px;"><b>已找到 ${s.result.length} 个解</b></div>`;
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}
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$('vizArea').innerHTML = viz;
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$('detailContent').innerHTML = '<div class="calc-block">' + s.msg + '</div>';
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if (s.stage==='done') $('resultContent').innerHTML = `<div class="final-answer">共 <b>${s.result.length}</b> 个解</div>`;
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$('hintText').textContent = s.msg;
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const stages = ['start→开始','try_valid→尝试放置','conflict→冲突','collect→收集解','undo→回溯','done→完成'];
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$('pipeline').innerHTML = stages.map(st => { const [k,l]=st.split('→'); return `<span class="pipe-step ${s.stage===k?'active':''}">${l}</span>`; }).join('<i>→</i>');
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}
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function init() {
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const sel = $('exampleSelect');
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examples.forEach((e,i) => { sel.innerHTML += `<option value="${i}">${e.label}</option>`; });
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$('inputArea').value = '4';
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buildSteps(examples[0].input);
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stepCtrl = new StepController({onStep: render});
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stepCtrl.setSteps(steps.map((_,i)=>i));
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$('stepInfo').textContent = '步骤 1 / ' + steps.length;
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stepCtrl.onStep = (idx) => { render(idx); $('stepInfo').textContent = `步骤 ${idx+1} / ${steps.length}`; };
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$('applyBtn').onclick = () => {
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const v = parseInt($('inputArea').value);
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if (isNaN(v)||v<1||v>8) { alert('请输入1-8的整数（8以上步骤过多）'); return; }
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buildSteps(v); stepCtrl.setSteps(steps.map((_,i)=>i)); render(0); $('stepInfo').textContent = '步骤 1 / ' + steps.length;
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};
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$('exampleSelect').onchange = () => {
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const e = examples[parseInt($('exampleSelect').value)];
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buildSteps(e.input); stepCtrl.setSteps(steps.map((_,i)=>i)); render(0);
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};
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$('prevBtn').onclick = () => stepCtrl.prev();
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$('nextBtn').onclick = () => stepCtrl.next();
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$('jumpBtn').onclick = () => stepCtrl.jumpToEnd();
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$('autoBtn').onclick = () => { const on = stepCtrl.toggleAuto(); $('autoBtn').textContent = on ? '暂停' : '自动播放'; };
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$('resetBtn').onclick = () => { stepCtrl.reset(); $('autoBtn').textContent = '自动播放'; };
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}
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init();
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$('codeArea').innerHTML = renderCode(`def solveNQueens(n):
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res = []
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def backtrack(row, queens):
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if row == n:
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res.append(queens[:])
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return
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for col in range(n):
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valid = True
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for r, c in enumerate(queens):
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if c == col or r+c == row+col or r-c == row-col:
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valid = False; break
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if valid:
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queens.append(col)
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backtrack(row + 1, queens)
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queens.pop()
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backtrack(0, [])
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return [['.'*c + 'Q' + '.'*(n-c-1) for c in sol] for sol in res]`, {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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