You are given an integer array nums and two integers minK and maxK. A fixed-bound subarray of nums is a subarray that satisfies the following conditions: The minimum value in the subarray is equal to minK. The maximum value in the subarray is equal

countSubarrays.js

/**
 * @param {number[]} nums
 * @param {number} minK
 * @param {number} maxK
 * @return {number}
 */
var countSubarrays = function(nums, minK, maxK) {
    // Initialize variables to keep track of indices and result
    let minI = -1; // Index of the last occurrence of minK
    let maxI = -1; // Index of the last occurrence of maxK
    let ans = 0; // Total count of valid subarrays
    let leftBoundary = -1; // Left boundary of the current subarray

    // Iterate through the input array
    for (let current = 0; current < nums.length; current++) {
        // Update minI and maxI if the current element matches minK or maxK
        if (nums[current] === minK) {
            minI = current;
        }

        if (nums[current] === maxK) {
            maxI = current;
        }

        // Update leftBoundary if the current element is outside the range [minK, maxK]
        if (nums[current] < minK || nums[current] > maxK) {
            leftBoundary = current;
        }

        // Calculate the valid subarray count and add it to the result
        let a = Math.min(minI, maxI) - leftBoundary;
        if (a > 0) {
            ans += a;
        }
    }

    return ans;
};