Content-Length: 5685 | pFad | http://github.com/TheAlgorithms/JavaScript/pull/1765.patch

thub.com From 2e2361e496eae35582208596ec293c4f747a836c Mon Sep 17 00:00:00 2001 From: k7 Date: Tue, 5 Nov 2024 22:27:57 +0530 Subject: [PATCH 1/2] feat: implement sliding window algorithms for fixed and dynamic sizes with tests --- .../LongestSubarrayWithSumAtMost.js | 21 +++++++++++++++ Sliding-Windows/MaxSumSubarrayFixed.js | 26 +++++++++++++++++++ .../test/LongestSubarrayWithSumAtMost.test.js | 24 +++++++++++++++++ .../test/MaxSumSubarrayFixed.test.js | 22 ++++++++++++++++ 4 files changed, 93 insertions(+) create mode 100644 Sliding-Windows/LongestSubarrayWithSumAtMost.js create mode 100644 Sliding-Windows/MaxSumSubarrayFixed.js create mode 100644 Sliding-Windows/test/LongestSubarrayWithSumAtMost.test.js create mode 100644 Sliding-Windows/test/MaxSumSubarrayFixed.test.js diff --git a/Sliding-Windows/LongestSubarrayWithSumAtMost.js b/Sliding-Windows/LongestSubarrayWithSumAtMost.js new file mode 100644 index 0000000000..b970539ee0 --- /dev/null +++ b/Sliding-Windows/LongestSubarrayWithSumAtMost.js @@ -0,0 +1,21 @@ +/** + * Function to find the longest subarray with a sum <= target. + * + * @param {number[]} arr - The input array of numbers. + * @param {number} target - The target sum for the dynamic window. + * @returns {number} - The length of the longest subarray with a sum <= target. + */ +export function longestSubarrayWithSumAtMost(arr, target) { + let maxLength = 0 + let windowSum = 0 + let left = 0 + for (let right = 0; right < arr.length; right++) { + windowSum += arr[right] + while (windowSum > target) { + windowSum -= arr[left] + left++ + } + maxLength = Math.max(maxLength, right - left + 1) + } + return maxLength +} diff --git a/Sliding-Windows/MaxSumSubarrayFixed.js b/Sliding-Windows/MaxSumSubarrayFixed.js new file mode 100644 index 0000000000..ba8b844f14 --- /dev/null +++ b/Sliding-Windows/MaxSumSubarrayFixed.js @@ -0,0 +1,26 @@ +/** + * Function to find the maximum sum of a subarray of fixed size k. + * + * @param {number[]} arr - The input array of numbers. + * @param {number} k - The fixed size of the subarray. + * @returns {number} - The maximum sum of any subarray of size k. + * @throws {RangeError} - If k is larger than the array length or less than 1. + */ +export function maxSumSubarrayFixed(arr, k) { + if (k > arr.length || k < 1) { + throw new RangeError( + 'Subarray size k must be between 1 and the length of the array' + ) + } + let maxSum = 0 + let windowSum = 0 + for (let i = 0; i < k; i++) { + windowSum += arr[i] + } + maxSum = windowSum + for (let i = k; i < arr.length; i++) { + windowSum += arr[i] - arr[i - k] + maxSum = Math.max(maxSum, windowSum) + } + return maxSum +} diff --git a/Sliding-Windows/test/LongestSubarrayWithSumAtMost.test.js b/Sliding-Windows/test/LongestSubarrayWithSumAtMost.test.js new file mode 100644 index 0000000000..c33188fffb --- /dev/null +++ b/Sliding-Windows/test/LongestSubarrayWithSumAtMost.test.js @@ -0,0 +1,24 @@ +import { longestSubarrayWithSumAtMost } from '../LongestSubarrayWithSumAtMost' + +describe('Dynamic-size Sliding Window - longestSubarrayWithSumAtMost', () => { + it('should return the longest subarray length with sum <= target', () => { + const arr = [1, 2, 3, 4, 5] + const target = 7 + const result = longestSubarrayWithSumAtMost(arr, target) + expect(result).toBe(3) + }) + + it('should return the full array length if the entire sum is within the target', () => { + const arr = [1, 1, 1, 1] + const target = 4 + const result = longestSubarrayWithSumAtMost(arr, target) + expect(result).toBe(4) + }) + + it('should return 0 if no subarray meets the sum condition', () => { + const arr = [5, 6, 7] + const target = 3 + const result = longestSubarrayWithSumAtMost(arr, target) + expect(result).toBe(0) + }) +}) diff --git a/Sliding-Windows/test/MaxSumSubarrayFixed.test.js b/Sliding-Windows/test/MaxSumSubarrayFixed.test.js new file mode 100644 index 0000000000..d4ca107c65 --- /dev/null +++ b/Sliding-Windows/test/MaxSumSubarrayFixed.test.js @@ -0,0 +1,22 @@ +import { maxSumSubarrayFixed } from '../MaxSumSubarrayFixed' + +describe('Fixed-size Sliding Window - maxSumSubarrayFixed', () => { + it('should return the maximum sum of a subarray of size k', () => { + const arr = [2, 1, 5, 1, 3, 2] + const k = 3 + const result = maxSumSubarrayFixed(arr, k) + expect(result).toBe(9) + }) + + it('should throw a RangeError if k is larger than the array length', () => { + const arr = [2, 1, 5] + const k = 4 + expect(() => maxSumSubarrayFixed(arr, k)).toThrow(RangeError) + }) + + it('should throw a RangeError if k is less than 1', () => { + const arr = [2, 1, 5] + const k = 0 + expect(() => maxSumSubarrayFixed(arr, k)).toThrow(RangeError) + }) +}) From a3c5ac035684dab66124b53961d6cf3e44e040a5 Mon Sep 17 00:00:00 2001 From: k7 Date: Tue, 5 Nov 2024 22:34:25 +0530 Subject: [PATCH 2/2] update directory file for sliding windows --- DIRECTORY.md | 3 +++ 1 file changed, 3 insertions(+) diff --git a/DIRECTORY.md b/DIRECTORY.md index 7f6484cae5..a29ece310e 100644 --- a/DIRECTORY.md +++ b/DIRECTORY.md @@ -322,6 +322,9 @@ * [StringSearch](Search/StringSearch.js) * [TernarySearch](Search/TernarySearch.js) * [UnionFind](Search/UnionFind.js) +* **Sliding-Windows** + * [MaxSumSubarrayFixed](Sliding-Windows/MaxSumSubarrayFixed.js) + * [LongestSubarrayWithSumAtMost](Sliding-Windows/LongestSubarrayWithSumAtMost.js) * **Sorts** * [AlphaNumericalSort](Sorts/AlphaNumericalSort.js) * [BeadSort](Sorts/BeadSort.js)

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