Merge k Sorted Lists: Min-Heap Priority Queue

You are given an array of `k` linked-lists `lists`, each linked-list is sorted in ascending order. Merge all the linked-lists into one sorted linked-list and return it. ### Input Format - First line contains an integer `k` (number of lists). - The next `k` lines each contain space-separated integers in ascending order for each list. An empty line represents an empty list. ### Output Format - Print space-separated integers representing the merged sorted elements, or an empty line if all lists are empty. ### Constraints - `k == lists.length` - `0 <= k <= 10^4` - `0 <= lists[i].length <= 500` - `-10^4 <= lists[i][j] <= 10^4`