20 lines
546 B
JavaScript
20 lines
546 B
JavaScript
const factors = (num, primes = false) => {
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const isPrime = num => {
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const boundary = Math.floor(Math.sqrt(num));
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for (var i = 2; i <= boundary; i++) if (num % i === 0) return false;
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return num >= 2;
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};
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const isNeg = num < 0;
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num = isNeg ? -num : num;
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let array = Array.from({ length: num - 1 })
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.map((val, i) => (num % (i + 2) === 0 ? i + 2 : false))
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.filter(val => val);
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if (isNeg)
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array = array.reduce((acc, val) => {
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acc.push(val);
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acc.push(-val);
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return acc;
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}, []);
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return primes ? array.filter(isPrime) : array;
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};
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module.exports = factors; |