A frustrating one for me. I spent a long time trying to understand why some combinations resulted in fewer presses and struggled to keep track of all the layers.

A few things that helped:

• shortest sequences will always use repeated keys e.g. V<<, never <V<
• if a sequence starts and ends on A, it is independent, cacheable and there is no need to keep track of the keys once summed

My solution:

Part 1 example (2.1ms): 126384
Part 1 input (0.9ms): 157908
Part 2 example (14.2ms): 154115708116294
Part 2 input (10.8ms): 196910339808654

I passed a cache map every but don’t like it. Is there a nicer way to cache without external deps or using Process? I’ll have a look into macros.