Initial commit

22.jl

@@ -0,0 +1,106 @@
+include("utils.jl")
+
+function interval(coords)
+    coords[1]:coords[2]
+end
+
+function parse_input(filename)
+    map(non_empty_lines(filename)) do line
+        command, coords = split(line)
+        coords = map(x->parse(Int, x.match), eachmatch(r"-?[0-9]+", coords))
+        coords = [interval(sort(coords[1:2])),
+                  interval(sort(coords[3:4])),
+                  interval(sort(coords[5:6]))]
+        command, coords
+    end
+end
+
+function ccontains(a, b)
+    all(issubset.(a, b))
+end
+
+function cempty(cube)
+    reduce(min, length.(cube)) == 0
+end
+
+function setdiffcubes(cube, subcube)
+    above = [cube[1],                              cube[2],                              (subcube[3].stop+1):(cube[3].stop)]
+    below = [cube[1],                              cube[2],                              (cube[3].start):(subcube[3].start-1)]
+    far =   [cube[1],                              (subcube[2].stop+1):(cube[2].stop),   subcube[3]]
+    near =  [cube[1],                              (cube[2].start):(subcube[2].start-1), subcube[3]]
+    right = [(subcube[1].stop+1):(cube[1].stop),   subcube[2],                           subcube[3]]
+    left =  [(cube[1].start):(subcube[1].start-1), subcube[2],                           subcube[3]]
+
+    filter(c->!cempty(c), [above, below, far, near, right, left])
+end
+
+function add_cube(cubes, cube)
+    if length(cubes) == 0
+        return [cube]
+    end
+
+    if any(map(c->ccontains(cube, c), cubes))
+        return cubes
+    end
+    cubes = filter(c->!ccontains(c, cube), cubes)
+
+    result = [cube]
+    for c in cubes
+        inter = intersect.(c, cube)
+        if cempty(inter)
+            push!(result, c)
+        else
+            append!(result, setdiffcubes(c, inter))
+        end
+    end
+    result
+end
+
+function remove_cube(cubes, cube)
+    if length(cubes) == 0
+        return []
+    end
+    result = []
+    for c in cubes
+        if ccontains(c, cube)
+            continue
+        end
+        inter = intersect.(c, cube)
+        if cempty(inter)
+            push!(result, c)
+            continue
+        end
+        append!(result, setdiffcubes(c, inter))
+    end
+    result
+end
+
+function magnitude(cube)
+    reduce(*, length.(cube))
+end
+
+function run(filter=nothing)
+    cubes = []
+    for (command, coords) in parse_input("22.data")
+        if typeof(filter) == Int64 && reduce(max, map(x->reduce(max, abs.(x)), coords)) > filter
+            continue
+        end
+        if command == "on"
+            cubes = add_cube(cubes, coords)
+        else
+            cubes = remove_cube(cubes, coords)
+        end
+    end
+    sum(map(magnitude, cubes))
+end
+
+
+function solution22_1()
+    run(50)
+end
+
+function solution22_2()
+    run()
+end
+
+solution22_1(), solution22_2()