day 18 ivy solution

day18/sol.ivy

@@ -0,0 +1,52 @@
+) get "input.ivy"
+
+sample = 13 3 rho 2 2 2 1 2 2 3 2 2 2 1 2 2 3 2 2 2 1 2 2 3 2 2 4 2 2 6 1 2 5 3 2 5 2 1 5 2 3 5
+#input = sample
+
+) origin 0
+
+op makeGrid coords =
+    lo = min/ transp coords
+    hi = max/ transp coords
+    coords = 1 1 1 + coords - lo
+    dim = 2 + (1 + hi - lo)
+    g = ,dim rho 0
+    g[dim decode transp coords] = 1
+    dim rho g
+
+op makeBorder dim =
+    g = (dim-2) rho 0
+    g = 1,(2 0 1 transp g),1
+    g = 1,(2 0 1 transp g),1
+    g = 1,(2 0 1 transp g),1
+    g
+
+op n twist a = 1 0 2 transp n flip (1 0 2 transp a)
+
+op grow a = (1 rot a) or (-1 rot a) or (1 flip a) or (-1 flip a) or (1 twist a) or (-1 twist a)
+op sides a = (1 rot a) + (-1 rot a) + (1 flip a) + (-1 flip a) + (1 twist a) + (-1 twist a)
+
+lava = makeGrid input
+
+"npoints = "; +/ ,lava
+#lava
+
+#border = makeBorder rho lava
+#or/, lava and border # should == 0
+
+op a flood walls =
+    x = grow a
+    b = (a or x) and not walls
+    and/, a == b: a
+    b flood walls
+
+op solve2 lava =
+    water = (makeBorder rho lava) flood lava
+    +/, lava * sides water
+
+op solve1 lava =
+    air = not lava
+    +/, lava * sides air
+
+"part 1 ="; solve1 lava
+"part 2 ="; solve2 lava