Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Computer Science Introduction to Data Structures Merge Sort and Linked Lists Implementing Merge Sort on Linked Lists

Eva Feng
Eva Feng
3,345 Points
Posted by Eva Feng
Eva Feng
3,345 Points

split function on the linked list

Hello If I modify the following code, mid_node = linked_list.node_at_index(mid - 1)

and replace with

mid_node = linked_list.node_at_index(mid)

It doesn't work, just wondering why? Theoretically it should not matter how I split the list, as there is stopping condition in place?

1 Answer

Steven Parker
Steven Parker
243,658 Points
Steven Parker
Steven Parker
243,658 Points

Consider the case where the list has 2 items. mid will therefore be 1, but 1 is the index of the last item. So the "left" list will have both items in it, and the "right" list will be empty. Recursively repeating the process will never produce two lists with a single item in each.