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28 lines
807 B
JavaScript
28 lines
807 B
JavaScript
export const findConvexHull = async (points) => {
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const _ = await import('https://cdn.jsdelivr.net/npm/lodash-es/+esm');
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const sorted = _.sortBy(_.uniqWith(points, _.isEqual), ['x', 'y']);
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if (sorted.length < 3) return sorted;
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const buildChain = (pts) => {
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const hull = [];
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for (const p of pts) {
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while (hull.length >= 2) {
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const a = hull[hull.length - 2];
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const b = hull[hull.length - 1];
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if ((b.x - a.x) * (p.y - a.y) - (b.y - a.y) * (p.x - a.x) > 0) break;
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hull.pop();
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}
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hull.push(p);
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}
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return hull;
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};
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const lower = buildChain(sorted);
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const upper = buildChain([...sorted].reverse());
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return [...lower.slice(0, -1), ...upper.slice(0, -1)];
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};
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export default findConvexHull;
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// Generation time: 17.558s
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// Result: PASS
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