I'm spending the weekend up in Michigan. Visiting my brother and is family. We're here to see the UMGASS production of Gilbert and Sullivan's The Sorcerer. Batya also came up from Cornell to join us so the two families are all togehter for the first time in about 10 years.

This hasn't left much time for Advent of Code but I did manage to finish yesterday's challenge this morning.

What took me so long? Much like last year, it was because I'm an idiot.

The problem seemed pretty straighforward. I coded a solution and it worked for all the test cases. I tried it on my data set but the grader said the answer was wrong. I went through the problem a number of times as well sa my code. I figured I either mis-interpreted the question or had some bug. I found neither to be true.

After some frustration, I went over to the Advent of Code subreddit grabbed a couple of posted solutions (trying not to look at them) and ran both on my data - those solutions got the same answer on my data set as I did.

This morning, I asked Batya to look over my code and the problem (it's always good to have a daughter that's smarted than you are) but she saw no problems.

Finally, I emailed my buddy JonAlf since I know he completed the problem. He sent back his answer along with his data set and I got the same answer as he did on his data.

What could be the problem.

His data set was about 12k characters long, mine was 4k. Something had to be wrong here. I went back to the Advent of Code site and grabbed the data set again. This time, I went to the page and did a "save-as" to save it - last time, I cut and pasted.

The cut and paste version was 4k, the save-as was 12k. This time it worked and was accepted and I also finished part 2 in short order.

The moral of the story – make sure you check the integrity of your data set - you'll never get the right answer if you're working with the wrong data.

In case anyone's interested, you can find my AoC code here.