Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)
You can send code in code blocks by using three backticks, the code, and then three backticks or use something such as https://topaz.github.io/paste/ if you prefer sending it through a URL
FAQ
What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268
Where do I participate?: https://adventofcode.com/
Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465
C++
No scala today
#include #include #include <map> #include #include #include #include #include #include #include #include struct HorizontalEdge { boost::icl::discrete_interval x; long y; }; long area(std::vector he) { if(he.empty()) return 0; boost::icl::interval_set intervals; std::ranges::sort(he, std::less{}, &HorizontalEdge::y); long area{}; long y = he.front().y; for(auto const& e : he) { area += intervals.size() * (e.y - std::exchange(y, e.y)); if(intervals.find(e.x) != intervals.end()) intervals.erase(e.x); else intervals.add(e.x); } return area; } struct Instruction { long l; int d; std::string color; }; enum Dir { R=0, U=1, L=2, D=3 }; std::unordered_map char_to_dir = {{'R', R}, {'U', U}, {'L', L}, {'D', D}}; auto transcode(std::vector const& is) { return flux::from(std::move(is)).map([](Instruction in) { long v = std::stoul(in.color.substr(0, 5), nullptr, 16); return Instruction{.l = v, .d = (4 - (in.color.at(5) - '0')) % 4, .color=""}; }).to>(); } std::vector read(std::string path) { std::ifstream in(std::move(path)); return flux::getlines(in).map([](std::string const& s) { Instruction i; char dir; if(auto r = scn::scan(s, "{} {} (#{:6})", dir, i.l, i.color)) { i.d = char_to_dir[dir]; return i; } else { throw std::runtime_error{r.error().msg()}; } }).to>(); } auto turns(std::vector is) { if(is.empty()) throw std::runtime_error{"Too few elements"}; is.push_back(is.front()); return flux::from(std::move(is)).pairwise_map([](auto const& lhs, auto const& rhs) { return (rhs.d - lhs.d + 4) % 4 == 1; }); } std::vector toEdges(std::vector is, bool left) { std::vector res; long x{}, y{}; auto t = turns(is).to>(); // some magic required to turn the ### path into its outer edge // (which is the actual object we want to compute the area for) for(size_t j = 0; j < is.size(); ++j) { auto const& i = is.at(j); bool s1 = t.at((j + t.size() - 1) % t.size()) == left; bool s2 = t.at(j) == left; long sign = (i.d == U || i.d == L) ? -1 : 1; long old_x = x; if(i.d == R || i.d == L) { x += i.l * sign; auto [l, r] = old_x < x ? std::tuple{old_x + !s1, x + s2} : std::tuple{x + !s2, old_x + s1}; res.push_back(HorizontalEdge{.x = {l, r, boost::icl::interval_bounds::right_open()}, .y = y}); } else { y += (i.l + s1 + s2 - 1) * sign; } } return res; } long solve(std::vector is) { auto tn = turns(is).sum() - ssize(is); return area(toEdges(std::move(is), tn > 0)); } int main(int argc, char* argv[]) { auto instructions = read(argc > 1 ? argv[1] : "../task1.txt"); auto start = std::chrono::steady_clock::now(); fmt::print("task1={}\ntask2={}\n", solve(instructions), solve(transcode(std::move(instructions)))); fmt::print("took {}\n", std::chrono::steady_clock::now() - start); } ```</map>
looks like some broken XSS protection is killing the includes, can't really fix that