Ah, some googling got me here: http://www.geeksforgeeks.org/merge-k-sorted-arrays/ http://www.geeksforgeeks.org/merge-k-sorted-arrays/ Merge k sorted arrays.

Ah, some googling got me here: http://www.geeksforgeeks.org/merge-k-sorted-arrays/ http://www.geeksforgeeks.org/merge-k-sorted-arrays/ Merge k sorted arrays. Obviously that's a job for a min heap (not heap sort though, just a heap to keep the values of the next item in each array).