lgrthms/lib/algorithms/sort/quickSort.js

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

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.quickSort = void 0;
const Comparator_1 = require("../../utils/Comparator");
const arrays_1 = require("../../utils/arrays");
// Best: O(nlog(n)) time | O(log(n)) space
// Avg: O(nlog(n)) time | O(log(n)) space
// Worst: O(n^2) time | O(log(n)) space
function quickSort(array, compareFn) {
    const comparator = new Comparator_1.Comparator(compareFn);
    doQuickSort(array, comparator, 0, array.length - 1);
    return array;
}
exports.quickSort = quickSort;
function doQuickSort(array, comparator, startIdx, endIdx) {
    if (endIdx <= startIdx) {
        return;
    }
    const pivotIdx = startIdx;
    let leftIdx = pivotIdx + 1;
    let rightIdx = endIdx;
    while (leftIdx <= rightIdx) {
        if (comparator.isGreaterThan(array[leftIdx], array[pivotIdx]) && comparator.isLessThan(array[rightIdx], array[leftIdx])) {
            (0, arrays_1.swap)(array, leftIdx, rightIdx);
        }
        if (comparator.isLessThanOrEqual(array[leftIdx], array[pivotIdx])) {
            leftIdx++;
        }
        if (comparator.isGreaterThanOrEqual(array[rightIdx], array[pivotIdx])) {
            rightIdx--;
        }
    }
    (0, arrays_1.swap)(array, pivotIdx, rightIdx);
    const leftLength = rightIdx - 1 - startIdx;
    const rightLength = endIdx - rightIdx + 1;
    if (leftLength <= rightLength) {
        doQuickSort(array, comparator, startIdx, rightIdx - 1);
        doQuickSort(array, comparator, rightIdx + 1, endIdx);
    }
    else {
        doQuickSort(array, comparator, rightIdx + 1, endIdx);
        doQuickSort(array, comparator, startIdx, rightIdx - 1);
    }
}