From f6a0447fa23e37aca7862e95e21a45d47311a406 Mon Sep 17 00:00:00 2001
From: j-james
Date: Sun, 30 May 2021 16:50:10 -0700
Subject: Day Seventeen, Part II

---
 2020/seventeen.nim | 52 ++++++++++++++++++++++++++++------------------------
 1 file changed, 28 insertions(+), 24 deletions(-)

diff --git a/2020/seventeen.nim b/2020/seventeen.nim
index 70c1cd4..8e4ab49 100644
--- a/2020/seventeen.nim
+++ b/2020/seventeen.nim
@@ -2,26 +2,27 @@
 import std/os, std/sets, std/enumerate
 
 let input: string = paramStr(1)
-type Coord = tuple[x,y,z: int]
+type Coord = tuple[x,y,z,w: int]
 
 # Coordinate system: 0,0 is at the top left
 var dimension: HashSet[Coord]
 for y, line in enumerate(lines(input)):
   for x, cube in line:
     if cube == '#':
-      dimension.incl((x,y,0))
+      dimension.incl((x,y,0,0))
       # stdout.write(x, ",", y, " ")
     # stdout.write(cube)
   # stdout.write('\n')
 # echo(dimension)
 
 ## Return a tuple describing a dimension's largest axes
-func maximum(dim: HashSet[Coord]): tuple[x,y,z: int] =
-  result = (0,0,0)
+func maximum(dim: HashSet[Coord]): tuple[x,y,z,w: int] =
+  result = (0,0,0,0)
   for cube in dim:
     if abs(cube.x) > result.x: result.x = abs(cube.x)
     if abs(cube.y) > result.y: result.y = abs(cube.y)
     if abs(cube.z) > result.z: result.z = abs(cube.z)
+    if abs(cube.w) > result.w: result.w = abs(cube.w)
 
 ## Return the number of cubes neighboring an arbitary point in space
 func neighbors(cube: Coord, dim: HashSet[Coord]): int =
@@ -29,8 +30,9 @@ func neighbors(cube: Coord, dim: HashSet[Coord]): int =
   for x in -1 .. 1:
     for y in -1 .. 1:
       for z in -1 .. 1:
-        if ((cube.x+x, cube.y+y, cube.z+z) in dim) and ((x,y,z) != (0,0,0)):
-          inc(result)
+        for w in -1 .. 1:
+          if ((cube.x+x, cube.y+y, cube.z+z, cube.w+w) in dim) and ((x,y,z,w) != (0,0,0,0)):
+            inc(result)
 
 ## Run one cycle of a pocket dimension
 func cycle(dim: HashSet[Coord]): HashSet[Coord] =
@@ -38,13 +40,14 @@ func cycle(dim: HashSet[Coord]): HashSet[Coord] =
   for x in -max.x-1 .. max.x+1:
     for y in -max.y-1 .. max.y+1:
       for z in -max.z-1 .. max.z+1:
-        let coord = (x,y,z)
-        if coord in dim:
-          if coord.neighbors(dim) == 2 or coord.neighbors(dim) == 3:
-            result.incl(coord)
-        if coord notin dim:
-          if coord.neighbors(dim) == 3:
-            result.incl(coord)
+        for w in -max.w-1 .. max.w+1:
+          let coord = (x,y,z,w)
+          if coord in dim:
+            if coord.neighbors(dim) == 2 or coord.neighbors(dim) == 3:
+              result.incl(coord)
+          if coord notin dim:
+            if coord.neighbors(dim) == 3:
+              result.incl(coord)
 
 func cycle(dim: HashSet[Coord], reps: int): HashSet[Coord] =
   result = dim
@@ -54,17 +57,18 @@ func cycle(dim: HashSet[Coord], reps: int): HashSet[Coord] =
 ## Visualize output
 proc echo(dim: HashSet[Coord]) =
   let max = maximum(dim)
-  for z in -max.z .. max.z:
-    stdout.write("z=", z, '\n')
-    for y in -max.y .. max.y:
-      for x in -max.x .. max.x:
-        if (x,y,z) == (0,0,0):
-          stdout.write('0')
-        elif (x,y,z) in dim:
-          stdout.write('#')
-        else:
-          stdout.write('.')
+  for w in -max.w .. max.w:
+    for z in -max.z .. max.z:
+      stdout.write("z=", z, ", ", "w=", w, '\n')
+      for y in -max.y .. max.y:
+        for x in -max.x .. max.x:
+          if (x,y,z,w) == (0,0,0,0):
+            stdout.write('0')
+          elif (x,y,z,w) in dim:
+            stdout.write('#')
+          else:
+            stdout.write('.')
+        stdout.write('\n')
       stdout.write('\n')
-    stdout.write('\n')
 
 echo len(dimension.cycle(6))
-- 
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