Reverse Nodes in K-Group, two ways

Try:
CALL
1 / 1

Code

The highlighted line runs next. The pill shows the live values in the running call.

Cost

Work done so far, and how the two solutions compare

The list

Nodes stay in place; only the next arrows change

Keyboard: ← → step, Space play or pause. 1 to 8 node values (0 to 100), and 1 ≤ k ≤ n. Nodes stay in their original positions inside their group bands, so a left-pointing arrow is a reversed link and an arc over the top jumps between groups. Only next pointers change; values never move.