programming-examples/js/Algorithms/insertion-binary-sort.js

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2019-11-15 12:59:38 +01:00
(function (exports) {
'use strict';
function comparator(a, b) {
return a - b;
}
/**
* Modified version of insertion sort. It uses binary search for finding
* where the current element should be inserted. It's correct because
* the binary search looks just in the first part of the array
* which is actually sorted.<br><br>
* Time complexity: O(N^2).
*
* @example
*
* var sort = require('path-to-algorithms/src' +
* '/sorting/insertion-binary-sort').insertionBinarySort;
* console.log(sort([2, 5, 1, 0, 4])); // [ 0, 1, 2, 4, 5 ]
*
* @public
* @module sorting/insertion-binary-sort
* @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.
*/
function insertionBinarySort(array, cmp) {
cmp = cmp || comparator;
var current;
var middle;
var left;
var right;
for (var i = 1; i < array.length; i += 1) {
current = array[i];
left = 0;
right = i;
middle = Math.floor((left + right) / 2);
while (left <= right) {
if (cmp(array[middle], current) <= 0) {
left = middle + 1;
} else if (cmp(array[middle], current) > 0) {
right = middle - 1;
}
middle = Math.floor((right + left) / 2);
}
for (var j = i; j > left; j -= 1) {
array[j] = array[j - 1];
}
array[j] = current;
}
return array;
}
exports.insertionBinarySort = insertionBinarySort;
})(typeof window === 'undefined' ? module.exports : window);