mirror of
https://github.com/TheAlgorithms/JavaScript.git
synced 2025-07-06 01:18:23 +08:00
chore: merge "repulling all together (#694)"
* Create slidingWindow.js * Rename slidingWindow.js to SlidingWindow.js * update the commit
This commit is contained in:

committed by
GitHub

parent
32359498ee
commit
3cae80e456
47
Search/SlidingWindow.js
Normal file
47
Search/SlidingWindow.js
Normal file
@ -0,0 +1,47 @@
|
|||||||
|
/**
|
||||||
|
* Sliding Window:
|
||||||
|
* This pattern involve creating a window which can either be
|
||||||
|
* an array or numbers from one position to another.
|
||||||
|
*
|
||||||
|
* Depending on a certain condition, the window either increases
|
||||||
|
* or closes (and a new window is created).
|
||||||
|
*
|
||||||
|
* Very useful for keeping track of a subset of data in an
|
||||||
|
* array/string etc.
|
||||||
|
*
|
||||||
|
* Time Complexity: Best - O(n);
|
||||||
|
*
|
||||||
|
* Examples:
|
||||||
|
* maxSubarraySum([1,2,5,2,8,1,5],2) // returns 10
|
||||||
|
* maxSubarraySum([1,2,5,2,8,1,5],15) // returns null
|
||||||
|
* maxSubarraySum([5,2,6,9],3) // returns 17
|
||||||
|
* @param {[Int]} arr - An array of integers on which we will perform the test.
|
||||||
|
* @param {Int} num - An integer that displays the size of the window you want to check.
|
||||||
|
* @returns {Int / Null} - Returns a total of N consecutive numbers or null
|
||||||
|
*/
|
||||||
|
|
||||||
|
function slidingWindow (arr, num) {
|
||||||
|
// Edge Case:
|
||||||
|
// If the length of the array shorter than the window size (num) return null.
|
||||||
|
if (arr.length < num) return null
|
||||||
|
// The highest amount of consecutive numbers
|
||||||
|
let maxSum = 0
|
||||||
|
// Temp amount of consecutive numbers - For comparative purposes
|
||||||
|
let tempSum = 0
|
||||||
|
// loop over the array {num} times and save their total amount in {maxSum}
|
||||||
|
for (let i = 0; i < num; i++) {
|
||||||
|
maxSum += arr[i]
|
||||||
|
}
|
||||||
|
// initialize {tempSum} to {maxSum}.
|
||||||
|
tempSum = maxSum
|
||||||
|
// loop over the array n times
|
||||||
|
for (let i = num; i < arr.length; i++) {
|
||||||
|
// Add the next num in the array and remove the first one
|
||||||
|
tempSum = tempSum - arr[i - num] + arr[i]
|
||||||
|
// save the largest number between {maxNum} and {tempNum} in maxSum.
|
||||||
|
maxSum = Math.max(maxSum, tempSum)
|
||||||
|
}
|
||||||
|
return maxSum
|
||||||
|
}
|
||||||
|
|
||||||
|
export { slidingWindow }
|
16
Search/test/SlidingWindow.test.js
Normal file
16
Search/test/SlidingWindow.test.js
Normal file
@ -0,0 +1,16 @@
|
|||||||
|
import { slidingWindow } from '../SlidingWindow'
|
||||||
|
|
||||||
|
test('expect to return the largest sum of sequence in the array', () => {
|
||||||
|
const sum = slidingWindow([1, 2, 5, 2, 8, 1, 5], 2)
|
||||||
|
expect(sum).toBe(10)
|
||||||
|
})
|
||||||
|
|
||||||
|
test('expect to return the largest sum of sequence in the array', () => {
|
||||||
|
const sum = slidingWindow([5, 2, 6, 9], 3)
|
||||||
|
expect(sum).toBe(17)
|
||||||
|
})
|
||||||
|
|
||||||
|
test('expect to return null when the sequence size is larger then the array length', () => {
|
||||||
|
const sum = slidingWindow([1, 2, 5, 2, 8, 1, 5], 15)
|
||||||
|
expect(sum).toBe(null)
|
||||||
|
})
|
Reference in New Issue
Block a user