aoc2021/19.jl

include("utils.jl")

function parse_input(filename)
    scanners = []
    current = []
    for line in non_empty_lines(filename)
        if line[1] == '-' && line[2] == '-'
            push!(scanners, current)
            current = []
        else
            coord = collect(map(m->parse(Int, m.match), eachmatch(r"-?[0-9]+", line)))
            push!(current, coord)
        end
    end
    push!(scanners, current)
    scanners[2:length(scanners)]
end

transforms = [
    # up: z
    a -> a,
    a -> [-a[2], a[1], a[3]],
    a -> [-a[1], -a[2], a[3]],
    a -> [a[2], -a[1], a[3]],
    # up: -z
    a -> [-a[1], a[2], -a[3]],
    a -> [a[2], a[1], -a[3]],
    a -> [a[1], -a[2], -a[3]],
    a -> [-a[2], -a[1], -a[3]],
    # up: x
    a -> [-a[3], a[2], a[1]],
    a -> [a[2], a[3], a[1]],
    a -> [a[3], -a[2], a[1]],
    a -> [-a[2], -a[3], a[1]],
    # up: -x
    a -> [a[3], a[2], -a[1]],
    a -> [-a[2], a[3], -a[1]],
    a -> [-a[3], -a[2], -a[1]],
    a -> [a[2], -a[3], -a[1]],
    # up: y
    a -> [a[1], -a[3], a[2]],
    a -> [-a[3], -a[1], a[2]],
    a -> [-a[1], a[3], a[2]],
    a -> [a[3], a[1], a[2]],
    # up: -y
    a -> [a[1], a[3], -a[2]],
    a -> [-a[3], a[1], -a[2]],
    a -> [-a[1], -a[3], -a[2]],
    a -> [a[3], -a[1], -a[2]],
]

function try_match(a, b)
    for c in a
        for d in b
            t = c - d
            if length(intersect(a, map(x->x+t, b))) > 11
                println("pos $t")
                #println(intersect(a, map(x->x+t, b)))
                return true, collect(map(x->x+t, b))
            end
        end
    end
    false, nothing
end

function find_match(fixed, scanners)
    for (f,j) in fixed
        for i in 1:length(scanners)
            s,k = scanners[i]
            for t in transforms
                td = collect(map(t, s))
                matchp, transformed = try_match(f, td)
                if matchp
                    println("f: $(j-1) s: $(k-1) ✓")
                    return i, transformed
                end
            end
#            println("f: $(j-1) s: $(k-1) x")
        end
    end
end

function solution19_1()
    scanners = collect(parse_input("19.data"))
    zipped = collect(zip(scanners, 1:length(scanners)))
    fixed = [popfirst!(zipped)]
    while length(zipped) > 0
        index, transformed = find_match(fixed, zipped)
        s = popat!(zipped, index)
#        println(s[1])
#        println(transformed)
        push!(fixed, (transformed, s[2]))
        l = length(fixed)
        println("located $l")
    end
    length(reduce(union, map(x->x[1], fixed)))
end

function solution19_2()
    positions = [[0, 0, 0],
                 [-28, 1245, -161],
                 [1163, 26, -170],
                 [-1254, 90, -158],
                 [-18, 1355, -1280],
                 [1146, -1193, -28],
                 [-2380, 15, -13],
                 [-1078, 63, 1010],
                 [-1105, 28, -1236],
                 [-12, 2400, -1318],
                 [-1075, 1190, -1385],
                 [-2348, 173, -1313],
                 [-2450, -1024, -26],
                 [-3547, 0, -79],
                 [-1233, -1211, 1144],
                 [-1092, 1288, 1125],
                 [-2449, 1277, -1238],
                 [-2290, -2266, -141],
                 [-4753, 30, -166],
                 [-3532, 97, 1132],
                 [-1224, 2573, 1061],
                 [-2428, 1249, 1069],
                 [-2269, -3556, -95],
                 [-1131, -2278, -172],
                 [-2337, -2411, 1197],
                 [-4722, 31, 1198],
                 [-6042, 159, -182],
                 [-3560, 131, 2245],
                 [-2385, -3457, 1117],
                 [-2369, -4811, -22],
                 [-1144, -3615, -89],
                 [-4732, -17, 2315],
                 [-5936, -1062, -10],
                 [-2339, -3488, 2394],
                 [-2334, -4684, 1017],
                 [-3472, -3589, 2361],
                 [-1256, -3495, 2220]]
    reduce(max, map(a->sum(abs.(a)), map(a->a[1]-a[2], [(a,b) for a in positions for b in positions])))
end

solution19_2()