algorithmpool/src/algopool/sort/countingSort.js

A pool of algorithms and data-structures for geeks

import {
    findMaxValue
} from '../search/maxMinSearch';

export const countingSort = (array) => {
    if (array.length < 2) {
        return array;
    }
    const maxValue = findMaxValue(array);
    let sortedIndex = 0;
    const counts = new Array(maxValue + 1);
    array.forEach(element => {
        if (!counts[element]) {
            counts[element] = 0;
        }
        counts[element]++;
    });
    // console.log('Frequencies: ' + counts.join());
    counts.forEach((element, i) => {
        while (element > 0) {
            array[sortedIndex++] = i;
            element--;
        }
    });
    return array;
}