Max Length of Subarray with Given Sum Limit in JavaScript Array

Given an array, our task is to find the maximum length of a subarray whose sum does not exceed a given value. We can use different approaches like the Brute Force Approach and the Sliding Window Approach to find the maximum length of a subarray.

Below are the approaches to find the maximum length of a subarray with a sum not exceeding a given value:

Using the Brute Force Approach

In this approach, the code employs a brute force method to find the maximum length of a subarray in JavaScript. It iterates through each possible subarray, calculating the sum and updating the maximum length if the sum does not exceed a given value k. Finally, the method returns the maximum length of the subarray with a sum not exceeding k.

Example: The example uses the Brute Force method to find the maximum length with the sum not exceeding a given value.

JavaScript

function maxSubarrayLengthBruteForce(arr, k) {
    let maxLength = 0;

    for (let start = 0; start < arr.length; start++) {
        let sum = 0;
        for (let end = start; end < arr.length; end++) {
            sum += arr[end];
            if (sum <= k) {
                maxLength = Math.max(maxLength, end - start + 1);
            }
        }
    }

    return maxLength;
}

const array1 = [1, 2, 3, 4, 5];
const k1 = 11;
console.log(maxSubarrayLengthBruteForce(array1, k1));
const array2 = [3, 1, 2, 1];
const k2 = 4;
console.log(maxSubarrayLengthBruteForce(array2, k2));

Output

4
3

Time Complexity: O(n^2)

Space Complexity: O(1)

Using the Sliding Window Approach

In this approach, the sliding window technique is used to find the maximum subarray length whose sum doesn’t exceed a given value k. It iterates through the array, adjusting the window boundaries to maintain the sum within k. Finally, it returns the maximum subarray length found.

Example: The example uses a sliding window technique to find the maximum subarray length with a sum not exceeding a given value.

JavaScript

function maxSubarrayLengthSlidingWindow(arr, k) {
    let maxLength = 0;
    let sum = 0;
    let start = 0;

    for (let end = 0; end < arr.length; end++) {
        sum += arr[end];
        while (sum > k) {
            sum -= arr[start];
            start++;
        }

        maxLength = Math.max(maxLength, end - start + 1);
    }

    return maxLength;
}
const array3 = [1, 2, 3, 4, 5];
const k3 = 11;
console.log(maxSubarrayLengthSlidingWindow(array3, k3));
const array4 = [3, 1, 2, 1];
const k4 = 4;
console.log(maxSubarrayLengthSlidingWindow(array4, k4));

Output

4
3

Time Complexity: O(n)

Space Complexity: O(1)