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21 lines
612 B
JavaScript
21 lines
612 B
JavaScript
async function findConvexHull(points){
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const m=await import('https://cdn.skypack.dev/lodash?min')
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const _=m.default||m
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const pts=_.sortBy(_.uniqWith(points,(a,b)=>a.x===b.x&&a.y===b.y),['x','y'])
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if(pts.length<3)return pts.slice()
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const h=[]
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const c=(o,a,b)=>(a.x-o.x)*(b.y-o.y)-(a.y-o.y)*(b.x-o.x)
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for(const p of pts){
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while(h.length>1&&c(h.at(-2),h.at(-1),p)<=0)h.pop()
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h.push(p)
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}
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const t=h.length+1
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for(let i=pts.length-2;i>=0;i--){
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const p=pts[i]
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while(h.length>=t&&c(h.at(-2),h.at(-1),p)<=0)h.pop()
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h.push(p)
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}
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h.pop()
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return h
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}
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export default findConvexHull; |