Given an array nums of n integers, your task is to find the maximum value of k for which there exist two adjacent subarrays of length k each, such that both subarrays are strictly increasing. Specifically, check if there are two subarrays of length k

maxIncreasingSubarrays.js

/**
 * @param {number[]} nums
 * @return {number}
 */
var maxIncreasingSubarrays = function (nums) {
    let maxK = 0;       // Stores the maximum valid k found so far
    let curLen = 1;     // Length of the current strictly increasing run
    let prevLen = 0;    // Length of the previous strictly increasing run

    for (let i = 1; i < nums.length; i++) {
        if (nums[i] > nums[i - 1]) {
            // Continue the current increasing run
            curLen++;
        } else {
            // End of an increasing run — evaluate possible k values

            // Case 1: Two adjacent increasing runs — take the smaller of the two
            // Case 2: A single long run — it can be split into two adjacent k-length runs
            maxK = Math.max(
                maxK,
                Math.floor(curLen / 2),      // Split one long run into two adjacent k-length runs
                Math.min(curLen, prevLen)    // Two adjacent runs of curLen and prevLen
            );

            // Shift current run to previous, and reset current
            prevLen = curLen;
            curLen = 1;
        }
    }

    // Final check after the loop ends (in case the array ends with an increasing run)
    maxK = Math.max(
        maxK,
        Math.floor(curLen / 2),
        Math.min(curLen, prevLen)
    );

    return maxK;
};