I know I’m not the only one finding day 3 frustrating.

My current code for day 3 is here. I find the locations of all of the special symbols, check around them to get the numbers, and dedup the list of numbers I find. To make things easier to debug, I generated some supplementary text files. One shows the input I used, but with all of the numbers I used replaced with 'x’s: the output doesn’t suggest any problems with my code that are obvious. The other has each number that went into the sum on its own line. I checked a few of these numbers and they seemed correct, but there are too many to check by hand.

What could I be doing wrong? I’ve officially run out of ideas.

  • damium@programming.dev
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    11 months ago

    If I’m reading it right I think the issue is using a HashSet to store the list of numbers for the sum. Some of the input numbers are repeated and the set discards them.

    I could be wrong though as I only just started learning rust for AoC.

    • CannotSleep420OP
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      11 months ago

      I originally used a Vec instead (so repeats are allowed) and my answer was still wrong. Whether or not the part numbers are supposed to be unique is something the problem didn’t specify.

      • snowe@programming.dev
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        11 months ago

        Any given number has a set of “coordinates”. That exact number can’t be repeated, even if it’s surrounded by symbols. But that number might be elsewhere in the list.

        edit:

        here’s an example:

        1.1
        .##
        2.3
        

        would give you a total of 7, because 1 and 1 are two different parts in the parts list. But the 1 in the top right is next two symbols, so you still only count it once. It’s just a single part! Think of them as parts rather than numbers. Each part is a different thing, even if they have the same name.

        • CannotSleep420OP
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          11 months ago

          I thought my checked_coord_set already made sure numbers next to more than one symbol were only counted once.