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20 lines
575 B
JavaScript
20 lines
575 B
JavaScript
export async function findConvexHull(p){
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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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p=_.uniqWith(p,_.isEqual)
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p=_.sortBy(p,['x','y'])
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const c=(a,b,d)=>(b.x-a.x)*(d.y-a.y)-(b.y-a.y)*(d.x-a.x)
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const h=[]
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for(const v of p){
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while(h.length>1&&c(h[h.length-2],h[h.length-1],v)<=0)h.pop()
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h.push(v)
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}
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const u=[]
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for(const v of [...p].reverse()){
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while(u.length>1&&c(u[u.length-2],u[u.length-1],v)<=0)u.pop()
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u.push(v)
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}
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h.pop()
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u.pop()
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return [...h,...u]
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}
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export default findConvexHull; |