@algorithm.ts/sieve-totient/lib/cjs/index.js

A linear time algorithm to sieve prime numbers and get the Euler's totient function

'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

function sieveTotient(N) {
    if (N < 1)
        return [new Uint32Array(0), []];
    if (N === 1)
        return [new Uint32Array(1), []];
    let tot = 0;
    const phi = new Uint32Array(N);
    const primes = [];
    phi[1] = 1;
    for (let x = 2; x < N; ++x) {
        if (phi[x] === 0) {
            primes[tot++] = x;
            phi[x] = x - 1;
        }
        for (let i = 0; i < tot; ++i) {
            const target = primes[i] * x;
            if (target >= N)
                break;
            if (x % primes[i] === 0) {
                phi[target] = phi[x] * primes[i];
                break;
            }
            phi[target] = phi[x] * (primes[i] - 1);
        }
    }
    primes.length = tot;
    return [phi, primes];
}

exports["default"] = sieveTotient;
exports.sieveTotient = sieveTotient;