Commit 7471d10

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better performance

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+32

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+32

-14

lines changed

Lines changed: 4 additions & 6 deletions

Original file line number	Diff line number	Diff line change
`@@ -2,13 +2,11 @@`
`2`	`2`
`3`	`3`	`Insertion sort is one of the most natural way of sorting. If you are given some cards that's probably how you are going to sort the.`
`4`	`4`
`5`		`-.This is how it works:`
`6`		`-. Start with the first element, assume that everything to its left is sorted and everything to the right is not.`
`7`		`-. Move to the next element.`
	`5`	`+Insertion sorts visit elements one by one. Everything to the left of the current element is curretly sorted and everything to the right is not.`
`8`	`6`
`9`		`-. Take the first element and consider it sorted.`
`10`		`-. Take the 2nd element, compare it with the first element. It 2nd is smaller swap it with the first element.`
`11`		`-. Go to the 3rd element compare it with the already sorted elements and if any of them is smaller, swap them.`
	`7`	`+.This is how it works:`
	`8`	`+. Visit 2nd. If the current element is smaller than the previous one move to the place it should be.`
	`9`	`+. Visit next element and do the same thing. The left is always sorted.`
`12`	`10`	`. Repeat for the rest of the array.`
`13`	`11`
`14`	`12`	`More efficient in practice than most other simple quadratic (i.e., O(n^2^)) algorithms such as <<Selection Sort>> or <<Bubble Sort>>.`

Lines changed: 5 additions & 8 deletions

Original file line number	Diff line number	Diff line change
`@@ -1,17 +1,14 @@`
`1`		`-const { swap } = require('./sorting-common');`
`2`		`-`
`3`	`1`	`function insertionSort(collection) {`
`4`	`2`	`const array = Array.from(collection);`
`5`	`3`
`6`		`- for (let outer = 1; outer < array.length; outer += 1) {`
	`4`	`+ for (let outer = 0; outer < array.length; outer += 1) {`
	`5`	`+ const insert = array[outer];`
`7`	`6`	`let inner = outer - 1;`
`8`		`- while (inner >= 0 && array[outer] < array[inner]) {`
	`7`	`+ while (inner >= 0 && array[inner] > insert) {`
	`8`	`+ array[inner + 1] = array[inner];`
`9`	`9`	`inner -= 1;`
`10`	`10`	`}`
`11`		`- if (outer !== inner + 1) {`
`12`		`- const [insert] = array.splice(outer, 1);`
`13`		`- array.splice(inner + 1, 0, insert);`
`14`		`- }`
	`11`	`+ array[inner + 1] = insert;`
`15`	`12`	`}`
`16`	`13`	`return array;`
`17`	`14`	`}`

Lines changed: 15 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,7 @@`
`1`	`1`	`// tag::swap[]`
`2`	`2`	`/**`
`3`	`3`	`* Swap array elements in place`
	`4`	`+ * Runtime: O(1)`
`4`	`5`	`* @param {array} array to be modified`
`5`	`6`	`* @param {integer} from index of the first element`
`6`	`7`	`* @param {integer} to index of the 2nd element`
`@@ -10,6 +11,20 @@ function swap(array, from, to) {`
`10`	`11`	`}`
`11`	`12`	`// end::swap[]`
`12`	`13`
	`14`	`+/**`
	`15`	`+ * Move an element in an array from a postion to another.`
	`16`	`+ * Runtime: O(n)`
	`17`	`+ * @param {array} array`
	`18`	`+ * @param {integer} from index of the element to remove (source)`
	`19`	`+ * @param {integer} to index where the removed element would be move (destination)`
	`20`	`+ */`
	`21`	`+function moveElement(array, from, to) {`
	`22`	`+ if (from === to + 1) return;`
	`23`	`+ const [elementToInsert] = array.splice(from, 1); // delete from position`
	`24`	`+ array.splice(to + 1, 0, elementToInsert); // insert element in to the position.`
	`25`	`+}`
	`26`	`+`
`13`	`27`	`module.exports = {`
`14`	`28`	`swap,`
	`29`	`+ moveElement,`
`15`	`30`	`};`

Lines changed: 8 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -5,6 +5,14 @@ const sortingAlgorithms = [`
`5`	`5`
`6`	`6`	`sortingAlgorithms.forEach((sort) => {`
`7`	`7`	describe(`Sorting with ${sort.name}`, () => {
	`8`	`+ it('should work with zero numbers', () => {`
	`9`	`+ expect(sort([])).toEqual([]);`
	`10`	`+ });`
	`11`	`+`
	`12`	`+ it('should work with one number', () => {`
	`13`	`+ expect(sort([3])).toEqual([3]);`
	`14`	`+ });`
	`15`	`+`
`8`	`16`	`it('should sort numbers', () => {`
`9`	`17`	`expect(sort([3, 5, 0])).toEqual([0, 3, 5]);`
`10`	`18`	`});`

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