lgrthms/lib/algorithms/sort/radixSort.js

Algorithms and data structures for your JavaScript and TypeScript projects 🧑‍💻

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.radixSort = void 0;
const NUMBER_BASE = 10;
function radixSort(array, direction, get) {
    if (array.length <= 1) {
        return array;
    }
    get = get ? get : (element) => element;
    let largest = -Infinity;
    for (const element of array) {
        const value = get(element);
        largest = Math.max(largest, value);
    }
    let pass = 0;
    while (Math.floor(largest / NUMBER_BASE ** pass) > 0) {
        countingSort(array, direction, get, pass);
        pass++;
    }
    return array;
}
exports.radixSort = radixSort;
function countingSort(array, direction, get, pass) {
    const counts = new Array(NUMBER_BASE).fill(0);
    const sorted = new Array(array.length);
    for (let i = 0; i < array.length; i++) {
        const value = get(array[i]);
        const radix = getRadix(value, pass);
        counts[radix]++;
    }
    if (direction === 'asc') {
        for (let i = 1; i < counts.length; i++) {
            counts[i] += counts[i - 1];
        }
    }
    else {
        for (let i = counts.length - 2; i >= 0; i--) {
            counts[i] += counts[i + 1];
        }
    }
    for (let i = array.length - 1; i >= 0; i--) {
        const element = array[i];
        const value = get(element);
        const radix = getRadix(value, pass);
        counts[radix]--;
        const sortedIndex = counts[radix];
        sorted[sortedIndex] = element;
    }
    for (let i = 0; i < sorted.length; i++) {
        array[i] = sorted[i];
    }
}
function getRadix(value, pass) {
    return Math.floor(value / NUMBER_BASE ** pass) % NUMBER_BASE;
}