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.*
Examples
Example 1
Input:
lists = [[1,4,5],[1,3,4],[2,6]]Output:
[1,1,2,3,4,4,5,6]The linked-lists are: [1->4->5, 1->3->4, 2->6]. Merging them into one sorted list: 1->1->2->3->4->4->5->6
Example 2
Input:
lists = []Output:
[]Example 3
Input:
lists = [[]]Output:
[]Constraints
- •
k == lists.length - •
0 <= k <= 10^4 - •
0 <= lists[i].length <= 500 - •
-10^4 <= lists[i][j] <= 10^4 - •
lists[i] is sorted in ascending order. - •
The sum of lists[i].length will not exceed 10^4.
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