Pattern visualizer

Merge k Sorted Lists

Merging two sorted lists always produces another sorted list, so that result can be fed straight back into the same merge step as if it were just another input list — there's no need for a different algorithm once k grows past two. Fold the lists together one at a time: merge list1+list2, merge that sorted result with list3, and so on, each step reusing the same two-pointer comparison as merging two lists. Reach for it when combining more than two sorted sequences. Animated on: Pairwise merge of 3 sorted lists: [1,4,5] + [1,3,4] → [1,1,3,4,5], then merged with [2,6] → [1,1,2,3,4,5,6].