In Java this year (again).
These will not be elegant. These may not be complete. These are definitely not recommended for use as examples.
- Elves' calories: Adding up lists of numbers
- Rock Paper Scissors: Determining outcomes
- Elves' rucksacks: Comparing items each elf is carrying
- Range pairs: Comparing overlapping and fully containing pairs of numbers
- Stacking supplies: Moving stacks of items between piles