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28 lines
808 B
JavaScript
28 lines
808 B
JavaScript
const findConvexHull = async points => {
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const _ = await import('https://cdn.jsdelivr.net/npm/lodash-es@4.17.21/lodash.js');
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const pts = _.sortBy(_.uniqWith(points, _.isEqual), ['x', 'y']);
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if (pts.length < 3) return pts;
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const cross = (o, a, b) => (a.x - o.x) * (b.y - o.y) - (a.y - o.y) * (b.x - o.x);
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const lower = [];
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for (const p of pts) {
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while (lower.length > 1 && cross(lower.at(-2), lower.at(-1), p) <= 0) lower.pop();
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lower.push(p);
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}
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const upper = [];
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for (let i = pts.length - 1; i >= 0; i--) {
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const p = pts[i];
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while (upper.length > 1 && cross(upper.at(-2), upper.at(-1), p) <= 0) upper.pop();
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upper.push(p);
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}
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lower.pop();
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upper.pop();
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return lower.concat(upper);
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};
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export default findConvexHull;
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// Generation time: 170.869s
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// Result: PASS
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