Problem Statement
You are given an array of k linkedlists lists, each linkedlist is sorted in ascending order.
Merge all the linkedlists into one sorted linkedlist and return it.
Example 1:


Example 2:


Example 3:


Constraints:
k == lists.length
0 <= k <= 104
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 exceed10^4
.
Test Cases


Solution
Solution 1: Python


Solution 2: Python


Here,
I use
count
as a second member for comparison for case when tuples has samel.val
 I could have used list indices as second member but they could also conflict.
 Because
count
will always be unique
Time complexity is
O(nlogk)
 Breakup:
O(klogk + n+ (nk)logk))
 Breakup: