programming-examples/js/Algorithms/shellsort.js
2019-11-15 12:59:38 +01:00

54 lines
1.4 KiB
JavaScript

(function (exports) {
'use strict';
function compare(a, b) {
return a - b;
}
var shellSort = (function () {
var gaps = [701, 301, 132, 57, 23, 10, 4, 1];
/**
* Shellsort which uses the gaps 701, 301, 132, 57, 23, 10, 4, 1 and
* insertion sort to sort sub-arrays which match for the different gaps.
*
* @example
*
* var sort = require('path-to-algorithms/src/' +
* 'sorting/shellsort').shellSort;
* console.log(sort([2, 5, 1, 0, 4])); // [ 0, 1, 2, 4, 5 ]
*
* @public
* @module sorting/shellsort
* @param {Array} array Input array.
* @param {Function} cmp Optional. A function that defines an
* alternative sort order. The function should return a negative,
* zero, or positive value, depending on the arguments.
* @return {Array} Sorted array.
*/
return function (array, cmp) {
cmp = cmp || compare;
var gap;
var current;
for (var k = 0; k < gaps.length; k += 1) {
gap = gaps[k];
for (var i = gap; i < array.length; i += gap) {
current = array[i];
for (var j = i;
j >= gap && cmp(array[j - gap], current) > 0; j -= gap) {
array[j] = array[j - gap];
}
array[j] = current;
}
}
return array;
};
}());
exports.shellSort = shellSort;
}(typeof exports === 'undefined' ? window : exports));