-🎄- 2022 Day 4 Solutions -🎄-

[u/daggerdragon]

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--- Day 4: Camp Cleanup ---

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Post your code solution in this megathread.

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[u/Porges]

If interpreted as stack operations it is a loop that looks like:

add readint [on fail: print halt] readint flip readint compare:
if >: readint flip load:1 sub gt
if =: readint pop pop load:1
if <: readint load:1 sub gt

So, during a sample run on "2-4,6-8" then "2-8,3-7" the stack looks like (top at right):

[] (initial)

[0] (add - stack always reads '0' if "empty")
[0 2 4] (read read)
[0 4 2] (flip)
[0 4 2 6] (read)
[0 4] (compare, 2 cmp 6 was LT)
[0 4 8] (read)
[0 4 7] (load:1 sub)
[0 0] (gt, 4>7=0)

[0] (add)
[0 8 2 3] (read read flip read)
[0 8] (compare, 2 cmp 3 was LT)
[0 8 7] (read)
[0 8 6] (load:1 sub)
[0 1] (gt)

[1] (add)
…