Parnic
4db2d11401
This one was a doozy and took far more time than I'd like to admit. I hope it's the hardest problem of the year. My original solution gave correct answers, but took on the order of 3+ minutes to run, even with memoization (it wasn't finishing any time soon without it). I then tried dropping in some A* and Dijkstra libraries, but wasn't really happy with how things were progressing with them. Some research pointed me toward double-ended queues and priority queues as better solutions, which I should have come up with my own since they've been used along with memoization in other AoC's, and dropping those in took the runtimes down to 4-15 seconds on my m1 macbook air. Once I swapped out the memoized data structures from arrays to maps, the runtime finally dropped to a much more palatable 50-180 millisecond range. I'm always suspicious when my solution is hundreds of lines of code, though, since you tend to see much more terse solutions from others in the AoC subreddit, but I attribute at least some of the bloat to "Go things" like how maps and arrays usually need to be "make"d first, how there's no easy "list comprehension" or "linq" style data structure queries, etc. Finally: note that I've seen _dramatically_ different runtimes based on the input. One set of input I checked against ran in 30ms/10ms while another ran in 180ms/54ms. I guess it's never been promised that all inputs are created equally...
5 lines
124 B
Plaintext
5 lines
124 B
Plaintext
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#f.D.E.e.C.b.A.@.a.B.c.#
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#d.....................#
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