Commit f738510

committed

merge sort

1 parent 9dc5caf commit f738510Copy full SHA for f738510

File tree

+53

-3

lines changed

+53

-3

lines changed

Lines changed: 3 additions & 3 deletions

Original file line number	Diff line number	Diff line change
`@@ -1,10 +1,10 @@`
`1`	`1`	`= Merge Sort`
`2`	`2`
`3`		`-Merge sort is an efficient sorting algorithm that uses "divide and conquer" paradigm to accomplish it task faster but it uses aditional storage in the process.`
	`3`	`+Merge sort is an efficient sorting algorithm that uses "divide and conquer" paradigm to accomplish it task faster. It uses auxiliary memory in the process of sorting.`
`4`	`4`
`5`	`5`	`== Merge Sort Implementation`
`6`	`6`
`7`		`-Merge sort can be implemented in any programming language. This are the general steps that this sorting algorithm follows:`
	`7`	`+Merge sort implementation is as follows`
`8`	`8`
`9`	`9`	`.Merge Sort Algorithm`
`10`	`10`	`. It moves one element at a time (from left to right). Everything on the left of the current element is already sorted, while everything to the right is not.`
`@@ -20,7 +20,7 @@ Let's convert these words into code!`
`20`	`20`	`.Merge Sort implementation in JavaScript`
`21`	`21`	`[source, javascript]`
`22`	`22`	`----`
`23`		`-include::{codedir}/algorithms/sorting/Merge-sort.js[tag=sort, indent=0]`
	`23`	`+include::{codedir}/algorithms/sorting/merge-sort.js[tag=sort, indent=0]`
`24`	`24`	`----`
`25`	`25`	`<1> Convert any kind of iterable (array, sets, etc.) into an array`
`26`	`26`	`<2> Start on the first element (position 0)`

Lines changed: 45 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,45 @@`
	`1`	`+function merge(array1, array2 = []) {`
	`2`	`+ const mergedLength = array1.length + array2.length;`
	`3`	`+ const mergedArray = [];`
	`4`	`+`
	`5`	`+ for (let index = 0, i1 = 0, i2 = 0; index < mergedLength; index += 1) {`
	`6`	`+ if (i2 >= array2.length \|\| (i1 < array1.length && array1[i1] < array2[i2])) {`
	`7`	`+ mergedArray[index] = array1[i1];`
	`8`	`+ i1 += 1;`
	`9`	`+ } else if (i1 >= array1.length \|\| (i2 < array2.length && array2[i2] < array1[i1])) {`
	`10`	`+ mergedArray[index] = array2[i2];`
	`11`	`+ i2 += 1;`
	`12`	`+ }`
	`13`	`+ }`
	`14`	`+`
	`15`	`+ return mergedArray;`
	`16`	`+}`
	`17`	`+`
	`18`	`+function splitSort(array) {`
	`19`	`+ const size = array.length;`
	`20`	`+ if (size < 2) {`
	`21`	`+ return array;`
	`22`	`+ } else if (size === 2) {`
	`23`	`+ return array[0] < array[1] ? array : [array[1], array[0]];`
	`24`	`+ }`
	`25`	`+ const middle = Math.ceil(size / 2);`
	`26`	`+`
	`27`	`+ return merge(`
	`28`	`+ splitSort(array.slice(0, middle)),`
	`29`	`+ splitSort(array.slice(middle)),`
	`30`	`+ );`
	`31`	`+}`
	`32`	`+`
	`33`	`+// tag::sort[]`
	`34`	`+/**`
	`35`	`+ * Merge sort`
	`36`	`+ * Runtime: O(n log n)`
	`37`	`+ * @param {Array\|Set} collection elements to be sorted`
	`38`	`+ */`
	`39`	`+function mergeSort(collection) {`
	`40`	`+ const array = Array.from(collection); // <1>`
	`41`	`+ return splitSort(array);`
	`42`	`+}`
	`43`	`+// end::sort[]`
	`44`	`+`
	`45`	`+module.exports = mergeSort;`

Lines changed: 5 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -2,6 +2,7 @@ const sortingAlgorithms = [`
`2`	`2`	`require('./selection-sort'),`
`3`	`3`	`require('./insertion-sort'),`
`4`	`4`	`require('./bubble-sort'),`
	`5`	`+ require('./merge-sort'),`
`5`	`6`	`];`
`6`	`7`
`7`	`8`	`sortingAlgorithms.forEach((sort) => {`
`@@ -33,5 +34,9 @@ sortingAlgorithms.forEach((sort) => {`
`33`	`34`	`it('should sort a set', () => {`
`34`	`35`	`expect(sort(new Set([3, 1, 2]))).toEqual([1, 2, 3]);`
`35`	`36`	`});`
	`37`	`+`
	`38`	`+ xit('should sort with duplicated values', () => {`
	`39`	`+ expect(sort([1, 3, 2, 1])).toEqual([1, 1, 2, 3]);`
	`40`	`+ });`
`36`	`41`	`});`
`37`	`42`	`});`

Comments

(0)