On: Advent of Code 2023 is nigh

[sebtron]

Ok, I'll be that guy... what edge case?

My part 2 was 4-line addition to part 1 (see code below, if inappropriate let me know and I'll remove it), and it worked first try. On the other hand, I made a mistake in part one and got it right only on a second attempt...

    (definition of nums[] omitted)
    for (j = 1; j < 10; j++)
         if (!strncmp(&buf[i], nums[j], strlen(nums[j])))
             buf[i] = j + '0';

[sixothree → sebtron]

I don't understand getting hit by an edge case either. Here's mine using Linq.

  var bestFirstValue = possibleValues
    .Where(x => currentLine.IndexOf(x.searchString) != -1)
    .OrderBy(x => currentLine.IndexOf(x.searchString))
    .First()
    .intValue;

[berkes → sebtron]

The most obvious edge-case was mentioned by other siblings.

My "edge case" is probably not really even an edge-case though.

SPOILER ALERT ---

My implementation stopped looking when it found a number. So "one2one" or "1twone" and so on, would find the numbers "1,2" and not "1,2,1". There were no examples where a number appeared multiple times in a line AND this affected the first-last pair. So e.g. abc1ninexyz841 would result in 14 in my case but should've been 11. Again: it's rather implied and quite obvious if you interpret the description as human, but I worked at it from TDD, and the example missed this situation and the actual input had only a relative few of them, so debugging was hard.

[Frummy → sebtron]

Edge cases such as "1oneight", "3sevenine", "sevenine3" (I made these up to highlight)

[mqus → Frummy]

Thanks! I thought I had the most straight-forward code there is and there were no edge cases that I hit. But I didn't use regex or something, just manual pattern matching like gp.

Imho regexes are overused for such stuff, precisely because they might do a lot of things you don't think about and are usually a lot slower than manually implementing what you want.

[sokoloff → Frummy]

I’d wager that most implementations would be fine on “sevenine3”, as they’d likely get 73 for the row, whether or not they found the 9.

[Frummy → sokoloff]

If they have functions that for example reads from forward then backward or vice versa while changing the structure of the row, one test will pass but the other won't. It's a lot of rows in the input and it took a lot of time for me personally to debug to understand what went wrong

[criddell → sokoloff]

How about just "sevenine"?