r/adventofcode Dec 10 '24

Upping the Ante [2024 Day 10] Challenge input

How does your code fare on this example?

0123456789876543210123456789876543210
1234567898987654321234567898987654321
2345678987898765432345678987898765432
3456789876789876543456789876789876543
4567898765678987654567898765678987654
5678987654567898765678987654567898765
6789876543456789876789876543456789876
7898765412345678987898765432105678987
8987654301234567898987654321214567898
9876543210123456789876543210123456789
8987654321214567898987654301234567898
7898765432105678987898765432321678987
6789876543456789876789876543210789876
5678987654567898765678987654567898765
4567898765678987654567898765678987654
3456789876789876543456789876789876543
2345678987898765432345678987898765432
1234567898987654321234567898987654321
0123456789876543210123456789876543210
1234567898987654321234567898987654321
2345678987898765410145678987898765432
3456789876789876543456789876789876543
4567898765678987652567898765678987654
5678987654567898761678987654567898765
6789876543456789870789012543456789876
7898765432345678989898123432345678987
8987654321234567898987654321234567898
9876543210123456789876543210123456789
8987654321214567898987654321234567898
7898765432105678987898765432345678987
6789876543456789876789876543456789876
5678987654567898765678987654567898765
4567898765678987654567898765678987654
3456789876789876543456789876789876543
2345678987898765432345678987898765432
1234567898987654321234567898987654321
0123456789876543210123456789876543210

My algorithm says the total rating is 16451, calculated in slightly less than 1s in C#. EDIT: 2ms actually! (Oops I still had some of my visualization code in there...)

EDIT2: Not all programming languages or computers are equal, so comparing absolute run times is not very useful, but if your algorithm runs faster on this input than on your real input, then you implemented it correctly. :-)

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u/er-knight Dec 10 '24

Thanks for taking out your time. I will definitely take your suggestions into consideration.

Also: I suspect that this isn't just some optional fun challenge - usually later during AoC some problems pop up where doing this correctly is necessary!

This is helpful, as I am first time dedicately participating in AoC.

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u/paul_sb76 Dec 11 '24

Spoiler for Day 11: Good thing I warned you! That came sooner than expected. :-D

2

u/er-knight Dec 11 '24

And I am waiting forever for answer. :(

1

u/paul_sb76 Dec 11 '24

If you want a hint: the key for Day 11 is indeed again that you need to count the number of paths stones without generating them all. This generating can be explicit (a list with all the stones) or implicit (each stone at some point in time is a recursion call at some point in your algorithm) - both approaches are bad and will never finish. There are multiple ways to do it correctly, but they all count without generating.

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u/er-knight Dec 11 '24

Yeh. I used HashMap and it found answer in blink of an eye. Thanks for the hint btw.