Tweaking Q solutions some more...

2015/10.q

@@ -1,7 +1,7 @@
 /--- Day 10: Elves Look, Elves Say ---
 
-res:{raze {count[x],first x}each cut[where differ x;x]}\[50;]10 vs "J"$ first read0 `:input/10.txt;
+res:{raze (1_deltas i,1),'x i:where differ x}\[50;]10 vs "J"$ first read0 `:input/10.txt
 count res 40
 /252594
 count res 50
-/3579328
+/3579328

2015/11.q

@@ -4,12 +4,12 @@ increment:{.Q.a 26 vs 1+26 sv -97+"j"$x}
 checkpass:{
   $[not any "iol" in x;
     $[1 in 1_deltas where 1=deltas "j"$x;
-      1<sum{ 1 in 1_deltas where x} each .Q.a=\:x;
+      1<sum{1 in 1_deltas where x} each .Q.a=\:x;
       0b];
     0b]
  }
 
-0N!res:{ increment x }/[{ not checkpass x };] first read0 `:input/11.txt;
+0N!res:increment/[{not checkpass x};] first read0 `:input/11.txt
 /vzbxxyzz
-{ increment x }/[{ not checkpass x };increment res]
+increment/[{not checkpass x};increment res]
 /vzcaabcc

2015/13.q

@@ -3,11 +3,11 @@
 a:`g`n`h xcols flip `g`h`n!("s  i      s";" ") 0: { -1_ssr[x;"lose ";"lose -"]} each read0`:input/13.txt
 
 combos:{ (1+count x)#'{raze y,/:'x except/:y}[x;]/[count[x]-1;x] }
-arrange:{ {[x;y] sum exec h from a where g in (x;y), n in (x;y) }.'-2#'prev\[count[x]-2;x] }
+arrange:{ {sum exec h from a where g in x, n in x} each -2#'prev\[count[x]-2;x] }
 
 max sum flip arrange each combos distinct (raze/)exec (g;n) from a
 /618
 
 / add myself and re-run
 max sum flip arrange each combos `me,distinct (raze/)exec (g;n) from a
-/601i
+/601i

2015/14.q

@@ -5,6 +5,6 @@ update p:0 from `f;
 
 max sum r:flip 2503#'{(x[`t]#x`s),x[`r]#0i } each f
 /2696
-{ update p:p+1 from `f where x = max x } each sums r;
+{ update p+1 from `f where x = max x } each sums r;
 exec max p from f
 /1084

2015/15.q

@@ -6,7 +6,7 @@ combos:{ { $[z=count x;enlist x,y;raze .z.s[;;z]'[x,/:t;y - t:til 1+y]] }[();x;y
 ingredients:`ing xkey flip `ing`cap`dur`fla`tex`cal!("s i i i i i";" ")0: except[;":,"] each read0 `:input/15.txt
 recipes:flip (0!ingredients)[`ing]!flip combos[100;4]
 
-max { (a~abs a)*prd 4#a:sum { ingredients[x]*y }'[key x;value x] } each recipes
+max { (a~abs a)*prd 4#a:sum { y*ingredients x }'[key x;value x] } peach recipes
 /222870
-max { (a[`cal]=500)*(a~abs a)*prd 4#a:sum { ingredients[x]*y }'[key x;value x] } each recipes
+max { (a[`cal]=500)*(a~abs a)*prd 4#a:sum { y*ingredients x }'[key x;value x] } peach recipes
 /117936

2015/18.q

@@ -1,19 +1,17 @@
 / --- Day 18: Like a GIF For Your Yard ---
 
-o:g:"#"=read0 `:input/18.txt; // build grid
+g:"#"=read0 `:input/18.txt; // build grid
 
 c:t cross t:til count g; // build coordinates
 
-i:{
-  s:sum .[g;] each (0  1;1  1;1  0;1 -1;0 -1;-1 -1;-1  0;-1  1)+\:x; / sum of neighbours
-  $[.[g;x]; / check state of current light
+f:{
+  s:sum .[x;] each (0  1;1  1;1  0;1 -1;0 -1;-1 -1;-1  0;-1  1)+\:y; / sum of neighbours
+  $[.[x;y]; / check state of current light
     s in 2 3;
     s = 3]
   };
 
-do[100;g:(2#count g)#i each c];
-
-sum raze g
+sum raze { (2#count x)#f[x;] peach c }/[100;g]
 /814
 
 / set corner lights on
@@ -26,10 +24,5 @@ sc:{
   x
  }
 
-/ reset grid and set corners on
-g:sc o;
-
-do[100;g:sc (2#count g)#i each c];
-
-sum raze g
+sum raze { sc (2#count x)#f[x;] peach c }/[100;sc g]
 / 924

2015/19.q

@@ -1,7 +1,7 @@
 /--- Day 19: Medicine for Rudolph ---
 
-r:r _ first where ""~/:r:read0 `:input/19.txt;
-s:flip string ("s s";" ")0:-1_r;
+r:r _ first where ""~/:r:read0 `:input/19.txt
+s:flip string ("s s";" ")0:-1_r
 
 count distinct raze { {[x;y;z;l] x:@[string x;y;:;z];raze x _/c#(y+c:count[l]-1) }[x;;z;y] each ss[x;y] }[last r;].'s
 /518

2015/24.q

@@ -14,9 +14,9 @@ f:{
 f2:{ f[x;1#y;y except first y] };
 
 r:f2[sum[i]%3;] i:desc "J"$read0 `:input/24.txt;
-(*/) r first iasc (*/) each r:r where c=min c:count each r
+prd r first iasc prd each r:r where c=min c:count each r
 /10439961859
 
 r:f2[sum[i]%4;i];
-(*/) r first iasc (*/) each r:r where c=min c:count each r
+prd r first iasc prd each r:r where c=min c:count each r
 /72050269

2017/13.q

@@ -2,7 +2,7 @@
 
 i:flip "J"$": "vs/:read0 `:input/13.txt
 f:@[(1+last l)#0N;l:first i;:;last i]
-sum f[w]*w:where 0=(til count g) mod g:{2*x-1}f
+sum w*f w:where 0=(til count g) mod g:{2*x-1}f
 /1476
-(2+)/[{max 0=(x+til count g) mod g};0] / slow, ~4s
+(2+)/[{max 0=(x+til count g) mod g};0] / ~4s
 /3937334

2017/14.q

@@ -6,22 +6,21 @@ sum raze h:raze each 0b vs''hash peach (first read0 `:input/14.txt),/:"-",'strin
 /8214
 
 v:(`u#enlist 0N 0N)!enlist 0N; / visited, add dummy value to setup key
-g:0;                           / group id
 
-f:{
-  if[not h[x;y];
+f:{[x;id]
+  if[not h . x;   / ignore 'off' bits
     :()
     ];
-  if[(x;y) in key v;
+  if[x in key v;  / ignore already visited
     :()
     ];
-  v[(x;y)]:g;
-  .z.s[x+1;y]; / go right
-  .z.s[x-1;y]; / go left
-  .z.s[x;y+1]; / go up
-  .z.s[x;y-1]; / go down
+  v[x]:id;
+  .z.s[x+1 0;id]; / go right
+  .z.s[x-1 0;id]; / go left
+  .z.s[x+0 1;id]; / go up
+  .z.s[x-0 1;id]; / go down
   };
 
-til[128]{g+:1;f[x;y]}\:/:til 128;
+f'[til[128] cross til 128;til 128*128];
 -1+count distinct value v
 /1093

2017/15.q

@@ -1,20 +1,13 @@
 /--- Day 15: Dueling Generators ---
 
-f:16807 48271
-m:2147483647
-c:0;
-{
-  c+:1*(~/) -16#'0b vs'x:(f*x) mod m;
-  x
- }/[40000000;f*i:first ("    i";" ") 0: `:input/15.txt];
-
-c
+g:{ (first[x]+(~/)mod[r;65536];r:(16807 48271*last x) mod 2147483647) }/[40000000;]
+first g (0;) i:first ("    j";" ") 0: `:input/15.txt
 /650
 
 A:B:()
 
-{ A,:$[0=mod[x:(first[f]*x) mod m;4];x;()];x }/[{ 5000000>count A };first i];
-{ B,:$[0=mod[x:(last[f]*x) mod m;8];x;()];x }/[{ 5000000>count B };last i];
+{ if[0=mod[x:(x*16807) mod 2147483647;4];A,:x mod 65536];x }/[{ 5000000>count A };first i];
+{ if[0=mod[x:(x*48271) mod 2147483647;8];B,:x mod 65536];x }/[{ 5000000>count B };last i];
 
-sum {x~y}'[(-16#'0b vs 'B);(-16#'0b vs'A)]
-/336
+sum A~'B
+/336

2017/24.q

@@ -1,16 +1,14 @@
 /--- Day 24: Electromagnetic Moat ---
 
-bridge:{
-  w:y~\:2#-1#x;
-  res:.z.s'[x,/:y where w;y _/:where w],
-      .z.s'[x,/:y where a;y _/:where a:not[w] and (last last x)=y[;0]],
-      .z.s'[x,/:reverse each y where a;y _/:where a:not[w] and (last last x)=y[;1]];
-  $[count res;res;x]
-  };
+f:{[bridge;options]
+  w1:where options[;0]=lc:last bridge; / options that match
+  w2:except[;w1] where options[;1]=lc; / options that match in reverse
+  if[0=count w1,w2;:enlist bridge];    / return if no further options
 
-flat:{ (raze .z.s each x where t),x where not t:0h=type each x };
+  raze .z.s'[bridge,/:(options w1),reverse each options w2;options _/:w1,w2];
+ }
 
-max sum each res:flat bridge[0;] "J"$"/"vs'read0 `:input/24.txt
+max sum each res:f[0;] "J"$"/"vs'read0 `:input/24.txt
 /1940
 max sum each res where c=max c:count each res
-/1928
+/1928

2019/02.q

@@ -52,7 +52,7 @@ if[`02.q~.z.f;
   I:"J"$"," vs first read0 `:input/02.txt;
 
   -1@string first first f[@[I;1 2;:;12 2];0];
-
+  /8017076
   N:0;V:0;T:19690720;W:1b;
 
   while[T>R:first first f[@[I;1 2;:;(N;V)];0];N+:1];