rocks = {}
pos_y = 0
for line in io.lines(arg[1]) do
    pos_x = 0
    for char in line:gmatch(".") do
        if char == "#" then
            table.insert(rocks, {y=pos_y, x=pos_x})
        end
        pos_x = pos_x + 1
    end
    pos_y = pos_y + 1
end
pos_y = nil
pos_x = nil

max = nil
for _, rock in ipairs(rocks) do
    count = 0
    angles_array = {}
    angles = {}
    for _, in_rock in ipairs(rocks) do
        if rock ~= in_rock then
            angle = math.atan(in_rock.y - rock.y, in_rock.x - rock.x) + math.pi / 2
            if angle < 0 then
                angle = angle + math.pi * 2
            end
            if angles[angle] == nil then
                angles[angle] = {in_rock}
                table.insert(angles_array, angle)
                count = count + 1
            else
                table.insert(angles[angle], in_rock)
            end
        end
    end
    if not max or max.count < count then
        max = {count=count, rock=rock, angles=angles, angles_array=angles_array}
    end
end

print(string.format("Part 1: %d (%d,%d)", max.count, max.rock.x, max.rock.y))

table.sort(max.angles_array)
for _, angle in ipairs(max.angles_array) do
    table.sort(max.angles[angle], function(x, y)
        local dist_x = math.sqrt((x.x - max.rock.x) ^ 2 + (x.y - max.rock.y) ^ 2)
        local dist_y = math.sqrt((y.x - max.rock.x) ^ 2 + (y.y - max.rock.y) ^ 2)
        return dist_x < dist_y
    end)
end

shot = 0
while true do
    for _, angle in ipairs(max.angles_array) do
        if #max.angles[angle] > 0 then
            shot = shot + 1
            if shot >= 200 then
                rock = max.angles[angle][#max.angles[angle]]
                print(string.format("Part 2: %d", rock.x * 100 + rock.y))
                os.exit(true)
            end
            max.angles[angle][#max.angles[angle]] = nil
        end
    end
end