Day 5: Cafeteria
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FAQ
- What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268
- Where do I participate?: https://adventofcode.com/
- Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465
It turns out that merging isn’t necessary, it’s simpler and slightly faster to just sort by starts. Part 2 then needs to remove any overlaps between adjacent ranges by setting end of each to min(end of this, start of next-1).
# AOC 2025 day 5 # D ← "3-5\n10-14\n16-20\n12-18\n\n1\n5\n8\n11\n17\n32" D ← &fras"2025day05.txt" # drop your input file on this pane and uncomment this line to test against your own data. Parse ← °⊟⍉⍆↯∞_2∩(⊜⋕⊸∊+@0⇡10)°$"_\n\n_" # split at \n\n; find all digits; sort ranges. P₁ ← /+≡(/↥)↧⊓⌟≥≤∩¤ # compare each against start/end arrays P₂ ← ⊙◌/+-⟜(↧⊓⬚∞↻₁(+1\↥)) # unmerge the ranges! simpler to count. ⍜now (⊃P₁ P₂ Parse D)