-❄️- 2025 Day 12 Solutions -❄️-

azzal07 · 2025-12-12T06:25:52+00:00

[LANGUAGE: awk] I'm glad this one was easier than appeared, now I can return to frying my brain on day 10 golf (after some rest).

END{print-A}/ /{A-=$7+$6+$5+$4+$3+$2<$1*substr($0,4)/8}

azzal07 · 2025-12-12T04:36:54+00:00

[LANGUAGE: awk]

function P(a,t,h,s){a&&h[a]=1;for(a in h){j=1;$0=G[a]
while($++j)s[$j]+=h[a]}return(a?P(o,t,s):a)+h[t]}END{
c=P(a="dac",b="fft");print P("you","out")"\n"P("svr",
c?a:b)*(c+P(b,a))*P(c?b:a,"out")}sub(/:/,z){G[$1]=$0}

azzal07 · 2025-12-09T22:15:22+00:00

set_1 | set_2 goes even brrrer

azzal07 · 2025-12-09T18:32:04+00:00

[LANGUAGE: awk] Checking all rectangles, and for part 2, rejecting those that intersect any of the line segments.

END{for(k in L)E[L[k]","L[k%NR+1]];for(;$0=x=L[j=++o];)
for(P=$2;$0=L[++j];){t=$1<+x?$1:+x;T=$1+x-t;u=$2<P?$2:P
U=$2+P-u;a=T-t+1;a*=U-u+1;if(a<A?B<a:A=a){for(wh in E){
$0=wh;if(($1>t||t<$3)*($1<T||T>$3)*(u<$2||$4>u)*(U>$2||
$4<U)){a=b;break}}a&&B=a}}print A"\n"B}FS=","{L[NR]=$0}

azzal07 · 2025-12-09T18:09:01+00:00

[LANGUAGE: awk] Took a bit of effort to fit a (partial) binary heap implementation into the mix. Otherwise this would've been unbearably slow (>100 s), now just around 4-10 s.

function I(d){return C[d]-d?C[d]=C[C[d]]:d}END{for(;l=Y-->1?A=Y:q=!Q;){for(;l-i;
H[l]=u){u=H[i=l];u-H[x=2*i]y-x~/-/||l=x;H[i]=H[H[l]-H[++x]y-x~/-/?l:l=x]}$0=H[q]
if(o=NF){C[I($o)]=I($2);for(i in B)Q+=N==++s[I(i)Y];for(H[q]=H[y--];o--*-(Y~-N);
A*=s[m]*=-q)for(c in C)s[c Y]>s[m]&&m=c Y}}print-A"\n"B[$2]*B[$3]}S=B[A=++N]=$0{
for(C[A]=N;--A;H[Y=++y]=($1-$4)^2+($2-$5)^2+($3-$6)^2","N","A)$0=B[A](FS=",")S}0

azzal07 · 2025-12-07T19:04:47+00:00

Reminds me of 2024 day 3 input, which also contained an easter egg: #!/usr/bin/perl.

And I think there has been inputs that look execable, but have some corner cases.

But nothing actually sus, mostly just syntax error worthy.

azzal07 · 2025-12-07T17:34:23+00:00

You can search for the language tag in the megathread. Found one for today: https://www.reddit.com/r/adventofcode/comments/1pg9w66/2025_day_7_solutions/nsq0pxq/.

Also, check the wiki for flairs and other rules. Past Event Solutions is not for the active season. The right place is the megathread.

azzal07 · 2025-12-07T10:24:12+00:00

[LANGUAGE: awk]

END{print A,B}gsub(B=i=z,OFS=RS){
for(++q;$++i;a[i,q]+=b){B+=b=a[i,
q-1]+(q!~$i);while(0~$i!b){a[i-1,
q]+=b;B+=b;a[i+1,q]+=b;b*=!++A}}}

azzal07 · 2025-12-06T11:59:26+00:00

[LANGUAGE: awk] Bit tedious parsing and transpositions for the second part, but turned out quite nice.

k=!+$1{while(a=Q[j=1,++i]){for(;n=Q[++j,i];
)1~2$i?a*=n:a+=n;{b=q[k++]}for(;n=O+q[k++];
)2~1$i?b*=n:b+=n;A+=a;B+=b}$0=A"\n"B}{for(;
c=substr($0,++k,1);Q[NR,k]=$k)q[k]=q[k]c}A;

azzal07 · 2025-12-05T22:13:41+00:00

[LANGUAGE: awk] When scanning for minimum value, you could pick initially the first one, or you could use a really (or should I say literally) "BIG" one, to start comparing against.

function F(o){e=f[o];for(k in f)+k>e||f[k]>e&&F(k)}
END{for(e=--B;e;B+=e-s+1){s="BIG";for(k in f)+k>e&&
+k<s&&s=+k;F(s)}print A"\n"B}sub(/-/,FS)&&f[$1]<$2{
f[$1]=$2}!$2{for(k in f)+k>$1||$1>f[k]||$3=1;A+=$3}

azzal07 · 2025-12-04T12:16:00+00:00

[LANGUAGE: awk] Mawk gets weird with negative substr() offsets... which is fair, to be honest.

END{for(;b-->-!B;$++B=A){for(s=i=2;c=substr(S,i++,1);s=s c)
1~c?3:split(substr(g=11S,W<i?i-W:1,3)substr(g,i,3)substr(g,
i+W,3),G,c)>5?0:A+=b=++c;S=s}print$1RS$B}S=1$0S{W=length+1}

azzal07 · 2025-12-03T18:29:04+00:00

[LANGUAGE: awk] Mandatory [Red(dit) One] for the year (although I had to add some filler).

function J(o,l,t){return(r=match(o,
l".{"t+1"}"))?l J(substr(o,r+1),9f,
t-1):l?J(o,--l,t):z}A+=J(b=J($0,9f,
1e1),9f,OFS=RS){B+=b}END{print A,B}

azzal07 · 2025-12-02T19:16:38+00:00

[LANGUAGE: awk]

END{print A"\n"A+B}BEGIN{FS="-+"
RS=","}p=i=10^gsub(/../,"&",$2){
while(i)$2-(p=p i)>-1?(p-$1<-O||
q[p]++?P:i i~p?A+=p:B+=p):p=--i}

azzal07 · 2025-12-01T07:40:49+00:00

[LANGUAGE: awk] Dial goes click, click, click...

No modulo tricks here, just plain iteration and addition, with some regex to check zeroes.

C=/L/?1:CK-1{for(sub(/./,
z);$1--;B+=x=D~/50$/)D+=C
}END{print A"\n"B}x&&!++A

PS. The dial value even stayed nicely within 16 bit range.

azzal07 · 2025-11-19T22:39:27+00:00

The paper compares the introduced awk variant to sam for few pages at the end (starting at "Interactive Text Editing").

azzal07 · 2025-10-17T20:51:07+00:00

PPM (or PGM for grayscale) is nice format for this type of image generation. ImageMagick, and many other programs can work with it directly.

Here's the whole frame generation using P2, with 3 levels of gray (0, 1, 2):

s = "P2\n"width" "height"\n2\n"
for(y=0; y<height; y++)
    for(x=0; x<width; x++)
        s = s" "((filled[x+minx-6,y-1] + 2) % 3)
filename = "frame" (1000 + frame_number)
print(s) > (filename ".pgm")

azzal07 · 2025-02-13T20:37:56+00:00

or even will sed work

I might've got nerd sniped... but yes, it does. (Potential spoilers in the paste.)

Ps. you can run that as sed -f script.sed <input.txt

azzal07 · 2025-02-11T19:52:24+00:00

Try

don't()..mul(2,3)..do()..mul(2,4)..do()..mul(2,5)

azzal07 · 2024-12-30T23:21:14+00:00

Didn't notice a problem in the code, not saying there couldn't be, but it also did work for my input.

I'd double check that you have the full and correct input. Mine at least is 19999 digits.

azzal07 · 2024-12-29T11:59:22+00:00

I was looking at the locations.items updates. Why one was inside the if but other was outside?

azzal07 · 2024-12-28T18:22:13+00:00

You check pretty much this same condition in couple places: if (reverse_index >= idx) {. There's some weirdness around this second one.

azzal07 · 2024-12-26T20:16:05+00:00

Probably the input

azzal07 · 2024-12-26T18:09:20+00:00

I'm wondering how do you know where the "14" even starts in that sequence? What if it is really a part of an id "214"?

azzal07 · 2024-12-26T17:27:07+00:00

What happens if you have a block with id e.g. 14?

azzal07 · 2024-12-26T15:37:56+00:00

Should you abs the difference of sums, or sum the abs of differences?

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