You have k lists of sorted integers. Find the smallest range that includes at least one number from each of the k lists.
For example,
List 1: [4, 10, 15, 24, 26]
List 2: [0, 9, 12, 20]
List 3: [5, 18, 22, 30]
The smallest range here would be [20, 24] as it contains 24 from list 1, 20 from list 2, and 22 from list 3.
Koderok 