@japan-d2/rho/lib/bigint/index.js

JavaScript implementation that compute prime factors using Pollard's rho algorithm

"use strict";
var __spreadArrays = (this && this.__spreadArrays) || function () {
    for (var s = 0, i = 0, il = arguments.length; i < il; i++) s += arguments[i].length;
    for (var r = Array(s), k = 0, i = 0; i < il; i++)
        for (var a = arguments[i], j = 0, jl = a.length; j < jl; j++, k++)
            r[k] = a[j];
    return r;
};
Object.defineProperty(exports, "__esModule", { value: true });
var bigint_1 = require("@japan-d2/gcd/lib/bigint");
function isPrime(n) {
    if (n === BigInt(1)) {
        return false;
    }
    if (n === BigInt(2) || n === BigInt(3)) {
        return true;
    }
    if ((n % BigInt(2) === BigInt(0)) || (n % BigInt(3) === BigInt(0))) {
        return false;
    }
    var p = BigInt(5);
    var w = BigInt(2);
    while (p * p <= n) {
        if (n % p === BigInt(0)) {
            return false;
        }
        p += w;
        w = BigInt(6) - w;
    }
    return true;
}
function f(x) {
    return x * x - BigInt(1);
}
function g(x) {
    return x * x + BigInt(1);
}
function rho(input, operator) {
    if (input % BigInt(2) === BigInt(0)) {
        return BigInt(2);
    }
    var n1 = BigInt(2);
    var n2 = BigInt(2);
    var divisor = BigInt(0);
    do {
        n1 = operator(n1) % input;
        n2 = operator(operator(n2)) % input;
        var nd = n1 > n2 ? n1 - n2 : n2 - n1;
        divisor = bigint_1.default(nd, input);
    } while (divisor === BigInt(1));
    if (divisor === input) {
        return rho(input, g);
    }
    return divisor;
}
function getFactorNumbers(n) {
    if (n === BigInt(1)) {
        return [BigInt(1)];
    }
    if (isPrime(n)) {
        return [n];
    }
    else {
        var divisor = rho(n, f);
        return __spreadArrays(getFactorNumbers(divisor), getFactorNumbers(n / divisor)).sort(function (a, b) {
            if (a === b)
                return 0;
            if (a > b)
                return 1;
            return -1;
        });
    }
}
exports.default = getFactorNumbers;