everyutil/array/shuffleStable.js

A comprehensive library of lightweight, reusable utility functions for JavaScript and TypeScript, designed to streamline common programming tasks such as string manipulation, array processing, date handling, and more.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.shuffleStable = void 0;
/**
 * Deterministic shuffle based on a seed.
 * @author @dailker
 * @template T
 * @param {T[]} array
 * @param {number} [seed=1]
 * @returns {T[]}
 */
function shuffleStable(array, seed = 1) {
    // Simple LCG for deterministic pseudo-random
    function random() {
        seed = (seed * 9301 + 49297) % 233280;
        return seed / 233280;
    }
    const arr = array.slice();
    for (let i = arr.length - 1; i > 0; i--) {
        const j = Math.floor(random() * (i + 1));
        [arr[i], arr[j]] = [arr[j], arr[i]];
    }
    return arr;
}
exports.shuffleStable = shuffleStable;