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35 lines
1010 B
JavaScript
35 lines
1010 B
JavaScript
async function findConvexHull(points) {
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const _ = (await import("https://cdn.jsdelivr.net/npm/lodash-es@4.17.21/lodash.min.js")).default
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|| await import("https://cdn.jsdelivr.net/npm/lodash-es@4.17.21/lodash.min.js");
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const unique = _.uniqWith(points, _.isEqual);
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const sorted = _.sortBy(unique, ["x", "y"]);
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if (sorted.length <= 1) return sorted;
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const cross = (O, A, B) =>
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(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 sorted) {
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while (lower.length >= 2 && cross(lower[lower.length - 2], lower[lower.length - 1], p) <= 0)
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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 = sorted.length - 1; i >= 0; i--) {
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const p = sorted[i];
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while (upper.length >= 2 && cross(upper[upper.length - 2], upper[upper.length - 1], p) <= 0)
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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: 5.389s
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// Result: PASS
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