Choose Three Disjoint Equal-Length Windows with Lexicographic Ties

### Problem Choose three nonoverlapping length-k contiguous subarrays of nums maximizing their combined sum. Return their starting indices in increasing order. Among equal-sum choices return the lexicographically smallest index triple. ```cpp class Solution { public: vector<int> maxSumOfThreeSubarrays(vector<int>& nums, int k); }; ``` ### Examples **Example 1:** ```text nums = [2,1,5,1,5,1], k = 1 Output: [0,2,4] Explanation: Values 2,5,5 give the maximum sum 12. ``` **Example 2:** ```text nums = [1,1,1,1,1,1,1], k = 2 Output: [0,2,4] Explanation: Every valid triple ties, so choose the earliest one. ``` ### Constraints - Array size: 1..20000. Values are positive and less than 65536. Window length k is between 1 and floor(nums.length/3). ### Clarifying Questions Enforce all three nonoverlap gaps and the lexicographically smallest maximizing triple. ```hint Read the boundary condition Once a middle window is fixed, can the best left and right windows be chosen independently? ``` ### Contract considerations Enforce all three nonoverlap gaps and the lexicographically smallest maximizing triple.