
Given an integer array nums and an integer k , find three non-overlapping subarrays of length k with maximum sum and return them.
Return the result as a list of indices representing the starting position of each interval ( 0-indexed ). If there are multiple answers, return the lexicographically smallest one.
1 <= nums.length <= 2 * 10 ^41 <= nums[i] < 2 ^161 <= k <= floor(nums.length / 3)