入力例のグラフを推定して、頂点と辺をSVG描画
// ==UserScript==
// @name AtCoder Graph Visualizer
// @namespace https://example.com/
// @version 1.3.0
// @description 入力例のグラフを推定して、頂点と辺をSVG描画
// @match https://atcoder.jp/contests/*/tasks/*
// @run-at document-idle
// @grant none
// @license MIT
// ==/UserScript==
(function () {
'use strict';
function el(tag, attrs = {}, children = []) {
const e = document.createElement(tag);
Object.entries(attrs).forEach(([k, v]) => {
if (k === 'style' && typeof v === 'object') Object.assign(e.style, v);
else if (k.startsWith('on') && typeof v === 'function') e.addEventListener(k.slice(2), v);
else e.setAttribute(k, v);
});
(Array.isArray(children) ? children : [children]).forEach(c => {
if (c == null) return;
if (typeof c === 'string') e.appendChild(document.createTextNode(c));
else e.appendChild(c);
});
return e;
}
function parseInts(line) {
return (line.match(/-?\d+/g) || []).map(s => Number(s));
}
function parseGraphFromSample(sampleText, forceTree = false) {
const lines = sampleText.replace(/\t/g, ' ').replace(/\r/g, '').split('\n')
.map(s => s.trim()).filter(s => s.length > 0);
const rows = lines.map(parseInts).filter(a => a.length > 0);
if (rows.length === 0) return null;
let N = null, M = null, edgeStartIdx = null;
if (forceTree) {
N = rows[0][0];
M = N - 1;
edgeStartIdx = 1;
} else if (rows[0].length >= 2) {
N = rows[0][0];
M = rows[0][1];
edgeStartIdx = 1;
} else if (rows[0].length === 1) {
if (rows.length >= 2 && rows[1].length === 1) {
N = rows[0][0];
M = rows[1][0];
edgeStartIdx = 2;
} else {
N = rows[0][0];
const edgeCandidates = rows.slice(1).filter(a => a.length >= 2);
if (edgeCandidates.length === N - 1 && N >= 2) {
M = N - 1;
edgeStartIdx = 1;
} else {
return null;
}
}
} else {
return null;
}
const edges = [];
let maxV = N || 0;
for (let i = 0; i < M; i++) {
const idx = edgeStartIdx + i;
if (idx >= rows.length) break;
const a = rows[idx];
if (a.length < 2) break;
const u = a[0], v = a[1];
const w = a.length >= 3 ? a[2] : null;
edges.push({ u, v, w });
maxV = Math.max(maxV, u, v);
}
if (edges.length === 0) return null;
const V = Math.max(N || 0, maxV);
if (!(V >= 1) || !(edges.length >= 1)) return null;
return { N: V, M: edges.length, edges };
}
function renderGraphSVG(graph, opts, width = 420, height = 420) {
const { N, edges } = graph;
const { directed, weighted } = opts;
const margin = 24;
const cx = width / 2, cy = height / 2;
const R = Math.min(width, height) / 2 - margin;
const pos = new Map();
for (let i = 1; i <= N; i++) {
const theta = (2 * Math.PI * (i - 1)) / N - Math.PI / 2;
pos.set(i, { x: cx + R * Math.cos(theta), y: cy + R * Math.sin(theta) });
}
const svgNS = 'http://www.w3.org/2000/svg';
const svg = document.createElementNS(svgNS, 'svg');
svg.setAttribute('width', String(width));
svg.setAttribute('height', String(height));
svg.style.display = 'block';
svg.style.border = '1px solid #ddd';
svg.style.borderRadius = '12px';
svg.style.marginTop = '8px';
svg.style.background = 'white';
if (directed) {
const defs = document.createElementNS(svgNS, 'defs');
const marker = document.createElementNS(svgNS, 'marker');
marker.setAttribute('id', 'arrowhead');
marker.setAttribute('markerWidth', '10');
marker.setAttribute('markerHeight', '7');
marker.setAttribute('refX', '10');
marker.setAttribute('refY', '3.5');
marker.setAttribute('orient', 'auto');
const path = document.createElementNS(svgNS, 'path');
path.setAttribute('d', 'M0,0 L10,3.5 L0,7 Z');
path.setAttribute('fill', '#555');
marker.appendChild(path);
defs.appendChild(marker);
svg.appendChild(defs);
}
edges.forEach(({ u, v, w }) => {
const pu = pos.get(u), pv = pos.get(v);
if (!pu || !pv) return;
const line = document.createElementNS(svgNS, 'line');
line.setAttribute('x1', pu.x.toFixed(2));
line.setAttribute('y1', pu.y.toFixed(2));
line.setAttribute('x2', pv.x.toFixed(2));
line.setAttribute('y2', pv.y.toFixed(2));
line.setAttribute('stroke', '#888');
line.setAttribute('stroke-width', '1.5');
if (directed) line.setAttribute('marker-end', 'url(#arrowhead)');
svg.appendChild(line);
if (weighted && w != null) {
const tx = (pu.x + pv.x) / 2, ty = (pu.y + pv.y) / 2;
const label = document.createElementNS(svgNS, 'text');
label.setAttribute('x', tx.toFixed(2));
label.setAttribute('y', ty.toFixed(2));
label.setAttribute('font-size', '11');
label.setAttribute('text-anchor', 'middle');
label.setAttribute('dominant-baseline', 'central');
label.setAttribute('fill', '#444');
label.textContent = String(w);
svg.appendChild(label);
}
});
for (let i = 1; i <= N; i++) {
const { x, y } = pos.get(i);
const g = document.createElementNS(svgNS, 'g');
const circle = document.createElementNS(svgNS, 'circle');
circle.setAttribute('cx', x.toFixed(2));
circle.setAttribute('cy', y.toFixed(2));
circle.setAttribute('r', '12');
circle.setAttribute('fill', '#f5f5f5');
circle.setAttribute('stroke', '#333');
circle.setAttribute('stroke-width', '1.5');
g.appendChild(circle);
const text = document.createElementNS(svgNS, 'text');
text.setAttribute('x', x.toFixed(2));
text.setAttribute('y', y.toFixed(2));
text.setAttribute('font-size', '12');
text.setAttribute('font-weight', '600');
text.setAttribute('text-anchor', 'middle');
text.setAttribute('dominant-baseline', 'central');
text.textContent = String(i);
g.appendChild(text);
svg.appendChild(g);
}
return svg;
}
function findSamplePreBlocks() {
const pres = [];
const headings = Array.from(document.querySelectorAll('h3, h4'));
headings.forEach(h => {
const txt = (h.textContent || '').trim();
if (/入力例|Sample Input/i.test(txt)) {
let el = h.nextElementSibling;
while (el && el.tagName.toLowerCase() !== 'pre') el = el.nextElementSibling;
if (el && el.tagName.toLowerCase() === 'pre') pres.push(el);
}
});
return pres;
}
function removeAllGraphs() {
document.querySelectorAll('.ac-graph-viz-container').forEach(e => e.remove());
}
function tryRenderForPre(pre) {
if (!pre) return;
const text = pre.textContent || '';
let directed = false;
let forceTree = false;
let weighted = false;
const svgArea = el('div', {});
function redraw() {
svgArea.innerHTML = '';
const graph = parseGraphFromSample(text, forceTree);
if (graph) {
svgArea.appendChild(renderGraphSVG(graph, { directed, weighted }));
} else {
svgArea.appendChild(el('div', { style: { fontSize: '12px', color: '#a00' } },
'グラフ入力を検出できなかったため描画をスキップした。'));
}
}
const directedBox = el('input', { type: 'checkbox', onchange: e => { directed = e.target.checked; redraw(); } });
const treeBox = el('input', { type: 'checkbox', onchange: e => { forceTree = e.target.checked; redraw(); } });
const weightedBox = el('input', { type: 'checkbox', onchange: e => { weighted = e.target.checked; redraw(); } });
const header = el('div', {
style: {
fontSize: '12px',
color: '#555',
marginBottom: '6px',
display: 'flex',
gap: '8px',
alignItems: 'center',
flexWrap: 'wrap',
}
}, [
el('span', {}, '🗺️ グラフ可視化（推定）'),
el('label', {}, [directedBox, ' 有向グラフ']),
el('label', {}, [treeBox, ' 木としてみる']),
el('label', {}, [weightedBox, ' 重み付きグラフ'])
]);
const container = el('div', {
class: 'ac-graph-viz-container',
style: { marginTop: '8px', marginBottom: '20px' }
}, [header, svgArea]);
pre.parentNode.insertBefore(container, pre.nextSibling);
redraw();
}
// --- ボタンを「入出力の形式」の下に置く ---
function injectToggle() {
const headings = Array.from(document.querySelectorAll('h3, h4'));
const target = headings.find(h => /入出力|入力/.test(h.textContent || ''));
if (!target) return;
if (document.getElementById('graph-toggle-container')) return;
let enabled = false;
const chk = el('input', { type: 'checkbox', id: 'graph-toggle-checkbox' });
chk.addEventListener('change', () => {
enabled = chk.checked;
removeAllGraphs();
if (enabled) {
findSamplePreBlocks().forEach(tryRenderForPre);
}
});
const container = el('div',
{
id: 'graph-toggle-container',
style: { margin: '6px 0', fontSize: '13px', color: '#333' }
},
[el('label', {}, [chk, ' 入力例からグラフを描画する'])]
);
target.parentNode.insertBefore(container, target.nextSibling);
}
function main() {
injectToggle();
}
main();
const mo = new MutationObserver(() => main());
mo.observe(document.documentElement, { childList: true, subtree: true });
})();