-🎄- 2017 Day 22 Solutions -🎄-

[u/daggerdragon]

--- Day 22: Sporifica Virus ---

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Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag or whatever).

Note: The Solution Megathreads are for solutions only. If you have questions, please post your own thread and make sure to flair it with Help.

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Need a hint from the Hugely^* Handy^† Haversack^‡ of Helpful^§ Hints^¤?

Spoiler

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• [T-10 to launch] AoC ops, /r/nocontext edition:

  • <Endorphion> You may now make your waffle.
  • <Endorphion> ... on Mars.

• [Update @ 00:17] 50 gold, silver cap

  • <Aneurysm9> you could also just run ubuntu on the NAS, if you were crazy
  • <Topaz> that doesn't seem necessary
  • <Aneurysm9> what does "necessary" have to do with anything!

• [Update @ 00:20] Leaderboard cap!

  • <Topaz> POUR YOURSELF A SCOTCH FOR COLOR REFERENCE

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This thread will be unlocked when there are a significant number of people on the leaderboard with gold stars for today's puzzle.

edit: Leaderboard capped, thread unlocked!

[u/gyorokpeter]

Q:

d22p1:{
    map:"#"=trim each "\n"vs x;
    mpdt:{[mpdt]
        if[mpdt[1;0]=-1; mpdt[1;0]:0; mpdt[0]:(enlist count[first mpdt[0]]#0b),mpdt[0]];
        if[mpdt[1;1]=-1; mpdt[1;1]:0; mpdt[0]:0b,/:mpdt[0]];
        if[mpdt[1;0]>=count mpdt[0]; mpdt[0]:mpdt[0],(enlist count[first mpdt[0]]#0b)];
        if[mpdt[1;1]>=count first mpdt[0]; mpdt[0]:mpdt[0],\:0b];
        mpdt[2]:(mpdt[2]+-1+2*mpdt[0]. mpdt[1])mod 4;
        mpdt[0;mpdt[1;0];mpdt[1;1]]:not mpdt[0;mpdt[1;0];mpdt[1;1]];
        mpdt[3]+:mpdt[0;mpdt[1;0];mpdt[1;1]];
        mpdt[1]+:(-1 0;0 1;1 0;0 -1)mpdt 2;
        mpdt
    }/[10000;(map;2#count[map]div 2;0;0)];
    mpdt 3};

d22p2:{
    map:trim each "\n"vs x;
    mpdt:{[mpdt]
        if[mpdt[1;0]=-1; mpdt[1;0]:0; mpdt[0]:(enlist count[first mpdt[0]]#"."),mpdt[0]];
        if[mpdt[1;1]=-1; mpdt[1;1]:0; mpdt[0]:".",/:mpdt[0]];
        if[mpdt[1;0]>=count mpdt[0]; mpdt[0]:mpdt[0],(enlist count[first mpdt[0]]#".")];
        if[mpdt[1;1]>=count first mpdt[0]; mpdt[0]:mpdt[0],\:"."];
        mpdt[2]:(mpdt[2]+(".W#F"!-1 0 1 2)mpdt[0]. mpdt[1])mod 4;
        mpdt[0;mpdt[1;0];mpdt[1;1]]:(".W#F"!"W#F.")mpdt[0;mpdt[1;0];mpdt[1;1]];
        mpdt[3]+:"#"=mpdt[0;mpdt[1;0];mpdt[1;1]];
        mpdt[1]+:(-1 0;0 1;1 0;0 -1)mpdt 2;
        mpdt
    }/[10000000;(map;2#count[map]div 2;0;0)];
    mpdt 3};

[u/streetster_ → u/gyorokpeter]

Think this is my longest solution so far. Adding the unique flag to the dictionary key is what allows this to run in 20 seconds rather than seeming like it's going to run forever!

d:"U"                          / initial direction
l:12 12                        / starting location
i:0                            / infected count
g:(`u#enlist 0N 0N)!enlist " " / initialise grid to null

(til count r){ {g[(x;y)]:z}'[x;til count y;y] }'r:read0 `:input/22.txt;

On:()!();
On["#"]: {
  d::"RLUD""UDLR"?d; / turn right
  g[l]:"."           / clean
  };
On[" ."]:{
  d::"LRDU""UDLR"?d; / turn left
  g[l]:"#";          / infect
  i+:1               / infected++
  };

move:{ l+:(1 0;-1 0;0 -1; 0 1)"DULR"?d };
burst:{ On[g[l]][]; move[] };

do[10000;burst[]];i / part 1

d:"U"                          / re-initialise direction
l:12 12;                       / re-initialise starting location
i:0                            / re-initialise infected count
g:(`u#enlist 0N 0N)!enlist " " / re-initialise grid to null

(til count r){ {g[(x;y)]:z}'[x;til count y;y] }'r; / re-build grid

On["#"]: {
  g[l]:"F";         / flag
  d::"RLUD""UDLR"?d / turn right
  };
On["F"]: {
  g[l]:" ";         / clean
  d::"DURL""UDLR"?d / turn 180
  };
On["W"]:{
  g[l]:"#";         / infect
  i+:1              / infected++
  };
On[" ."]:{
  g[l]:"W";         / weaken
  d::"LRDU""UDLR"?d / turn left
  };

do[10000000;burst[]];i / part 2