113 lines
2.9 KiB
JavaScript
113 lines
2.9 KiB
JavaScript
(function (exports) {
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'use strict';
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var bucketSort = (function () {
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/**
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* Insertionsort.
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*
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* @private
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* @param {array} array Input array
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* @returns {array} array Sorted input array
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*/
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function insertionSort(array) {
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var current;
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var j;
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for (var i = 1; i < array.length; i += 1) {
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current = array[i];
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j = i - 1;
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while (j >= 0 && current < array[j]) {
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array[j + 1] = array[j];
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j -= 1;
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}
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array[j + 1] = current;
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}
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return array;
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}
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/**
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* Creates buckets for given array
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*
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* @private
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* @param {array} array Input array
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* @returns {array} buckets Array whith array for each bucket.
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* Each bucket contains an array with all elements
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* from the input which are with suitable size.
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*/
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function createBuckets(array) {
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var buckets = [];
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var currentBucket;
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var current;
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for (var i = 0; i < array.length; i += 1) {
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current = array[i];
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currentBucket = Math.floor(current);
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buckets[currentBucket] = buckets[currentBucket] || [];
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buckets[currentBucket].push(current);
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}
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return buckets;
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}
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/**
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* Sorts the arrays from each bucket.
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*
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* @private
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* @param {array} buckets Given buckets
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* @returns {array} buckets Buckets with sorted arrays for each bucket
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*/
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function sortBuckets(buckets) {
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for (var i = 0; i < buckets.length; i += 1) {
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if (buckets[i] !== undefined) {
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insertionSort(buckets[i]);
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}
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}
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return buckets;
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}
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/**
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* Unions all buckets' arrays
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*
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* @private
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* @param {array} buckets Input buckets
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* @returns {array} result Sorted array which contains
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* all elements form each bucket
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*/
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function unionBuckets(buckets) {
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var result = [];
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var currentBucket;
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for (var i = 0; i < buckets.length; i += 1) {
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currentBucket = buckets[i];
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if (currentBucket !== undefined) {
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result = result.concat(currentBucket);
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}
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}
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return result;
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}
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/**
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* Sorts given array with bucketsort.<br><br>
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* Time complexity: O(N) in case the
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* data is with uniform distribution.
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*
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* @example
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*
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* var sort = require('path-to-algorithms/src/'+
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* 'sorting/bucketsort').bucketSort;
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* console.log(sort([2, 5, 1, 0, 4])); // [ 0, 1, 2, 4, 5 ]
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*
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* @public
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* @module sorting/bucketsort
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* @param {Array} array Input array which should be sorted.
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* @return {Array} Sorted array.
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*/
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return function (array) {
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var buckets = createBuckets(array);
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sortBuckets(buckets);
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return unionBuckets(buckets);
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};
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}());
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exports.bucketSort = bucketSort;
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})(typeof window === 'undefined' ? module.exports : window);
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