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27 lines
699 B
JavaScript
27 lines
699 B
JavaScript
function sieveOfEratosthenes (n) {
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/*
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* Calculates prime numbers till a number n
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* :param n: Number upto which to calculate primes
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* :return: A boolean list containing only primes
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*/
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const primes = new Array(n + 1)
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primes.fill(true) // set all as true initially
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primes[0] = primes[1] = false // Handling case for 0 and 1
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const sqrtn = Math.ceil(Math.sqrt(n))
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for (let i = 2; i <= sqrtn; i++) {
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if (primes[i]) {
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for (let j = 2 * i; j <= n; j += i) {
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primes[j] = false
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}
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}
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}
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return primes
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}
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// Example
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// const n = 69 // number till where we wish to find primes
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// const primes = sieveOfEratosthenes(n)
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export { sieveOfEratosthenes }
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