Look-and-Say Consolidation

Traverse a linked list and identify consecutive runs of the same value. Replace each run with two nodes: the value and the length of the run. The order of these two nodes depends on the length: if the length is even, the length node must come BEFORE the value node. If the length is odd, the length node must come AFTER the value node. Example: Input: 2 2 2 3 3 1 - Run 1: Value 2, Length 3 (odd) -> 2 3 - Run 2: Value 3, Length 2 (even) -> 2 3 - Run 3: Value 1, Length 1 (odd) -> 1 1 Output: 2 3 2 3 1 1