50 lines
1.1 KiB
JavaScript
50 lines
1.1 KiB
JavaScript
'use strict';
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import _ from '../utils';
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let arr = _.args.numbers();
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function quickSort(array, p = 0, r = array.length) {
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if (p >= r) return;
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let pivot = partition(array, p, r);
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// pivot is not included
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quickSort(array, p, pivot - 1);
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quickSort(array, pivot + 1, r);
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}
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function partition(array, p, r) {
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let q = p;
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// start at p, if any element is bigger than pivot, it will automatically
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// be added to RIGHT group as the u increases,
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// if it's less than pivot, it will be added to LEFT by swapping it
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// with the leftmost element of RIGHT group, and moving RIGHT's starting point
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// (q) one point to right
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for (let u = p; u < r; u++) {
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if (array[u] <= array[r]) {
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swap(array, u, q);
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q++;
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}
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}
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// after finding LEFT and RIGHT groups, move pivot to it's original position
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swap(array, r, q);
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return q;
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}
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function swap(array, a, b) {
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let tmp = array[b];
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array[b] = array[a];
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array[a] = tmp;
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}
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if (require.main === module) {
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quickSort(arr, 0, arr.length);
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_.log(arr.join(' '));
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}
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module.exports = quickSort;
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