this post was submitted on 05 Dec 2024
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Advent Of Code
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An unofficial home for the advent of code community on programming.dev!
Advent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.
AoC 2024
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console.log('Hello World')
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C
I got the question so wrong - I thought a|b and b|c would imply a|c so I went and used dynamic programming to propagate indirect relations through a table.
It worked beautifully but not for the input, which doesn't describe an absolute global ordering at all. It may well give a|c and b|c AND c|a. Nothing can be deduced then, and nothing needs to, because all required relations are directly specified.
The table works great though, the sort comparator is a simple 2D array index, so O(1).
Code
https://github.com/sjmulder/aoc/blob/master/2024/c/day05.c
Same, I initially also thought a|b and a|c implies a|c. However when I drew the graph of the example on paper, I suspected that all relations will be given, and coded it with that assumption, that turned out to be correct