Commit d59cc09

authored

Merge pull request knaxus#78 from gabrielbarker/jumpSearch

Add jumpSearch and Tests

2 parents 7ca7bd9 + 9d2da8f commit d59cc09Copy full SHA for d59cc09

File tree

+58

-0

lines changed

+58

-0

lines changed

Lines changed: 20 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,20 @@`
	`1`	`+const { jumpSearch, jumpSearchRecursive } = require('.');`
	`2`	`+`
	`3`	`+describe('Jump Search', () => {`
	`4`	`+ const array = [1, 2, 3, 4, 5, 6, 7, 8];`
	`5`	`+ describe('When element to find is at 1st position ', () => {`
	`6`	`+ it('Jump search', () => {`
	`7`	`+ expect(jumpSearch(array, 1)).toEqual(0);`
	`8`	`+ });`
	`9`	`+ });`
	`10`	`+ describe('When element to find is at last position ', () => {`
	`11`	`+ it('Jump search', () => {`
	`12`	`+ expect(jumpSearch(array, 7)).toEqual(6);`
	`13`	`+ });`
	`14`	`+ });`
	`15`	`+ describe('When element to find is at random position ', () => {`
	`16`	`+ it('Jump search', () => {`
	`17`	`+ expect(jumpSearch(array, 3)).toEqual(2);`
	`18`	`+ });`
	`19`	`+ });`
	`20`	`+});`

Lines changed: 38 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,38 @@`
	`1`	`+/**`
	`2`	`+ * Note: Array must be sorted for jump search`
	`3`	`+ * Complexity:`
	`4`	`+ * Worst case time complexity: O(√N)`
	`5`	`+ * Average case time complexity: O(√N)`
	`6`	`+ * Best case time complexity: O(1)`
	`7`	`+ * Space complexity: O(1)`
	`8`	`+*/`
	`9`	`+function jumpSearch(arr, key) {`
	`10`	`+ const n = arr.length;`
	`11`	`+ const jump = Math.floor(Math.sqrt(n));`
	`12`	`+ let step = jump;`
	`13`	`+`
	`14`	`+ let prev = 0;`
	`15`	`+`
	`16`	`+ while(arr[Math.min(step, n) - 1] < key) {`
	`17`	`+ prev = step;`
	`18`	`+ step += jump;`
	`19`	`+ if (prev >= n)`
	`20`	`+ return null;`
	`21`	`+ }`
	`22`	`+`
	`23`	`+ while(arr[prev] < key) {`
	`24`	`+ prev++;`
	`25`	`+`
	`26`	`+ if (prev == Math.min(step, n))`
	`27`	`+ return null;`
	`28`	`+ }`
	`29`	`+`
	`30`	`+ if (arr[prev] == key)`
	`31`	`+ return prev;`
	`32`	`+`
	`33`	`+ return null;`
	`34`	`+ }`
	`35`	`+`
	`36`	`+ module.exports = {`
	`37`	`+ jumpSearch,`
	`38`	`+ };`

Comments

(0)