diff options
| author | Clyne Sullivan <clyne@bitgloo.com> | 2022-12-15 08:42:50 -0500 |
|---|---|---|
| committer | Clyne Sullivan <clyne@bitgloo.com> | 2022-12-15 08:42:50 -0500 |
| commit | e54a0068c9fe99832a85cd459cd31f2b8967f45a (patch) | |
| tree | d0259d6ba1b72bc85cbb41a004557a4171061a34 | |
| parent | b6e660ac61a927e517b355cd8d20ddcabc3c9b75 (diff) | |
day15: finish part 2 c++
| -rw-r--r-- | day15/part2.cpp | 65 |
1 files changed, 37 insertions, 28 deletions
diff --git a/day15/part2.cpp b/day15/part2.cpp index 6a80e54..708f389 100644 --- a/day15/part2.cpp +++ b/day15/part2.cpp @@ -7,49 +7,58 @@ struct Sensor { long x, y, power; - Sensor(long xx, long yy, long pp): + Sensor(long xx, long yy, long pp = 0): x(xx), y(yy), power(pp) {} }; -int main() +std::vector<Sensor> sensors; + +bool isDistressBeacon(const Sensor& c) { - std::vector<Sensor> sensors; - long px, py, bx, by; + if (c.x < 0 || c.x > 4000000 || c.y < 0 || c.y > 4000000) + return false; + + bool found = true; + uint64_t freq = 0; - do { - std::string line; - std::getline(std::cin, line); - if (std::cin.eof()) + for (auto& s : sensors) { + auto dist = std::abs(c.x - s.x) + std::abs(c.y - s.y); + if (dist <= s.power) { + found = false; break; + } + } + + return found; +} +int main() +{ + long px, py, bx, by; + + std::string line; + std::getline(std::cin, line); + for (; !std::cin.eof(); std::getline(std::cin, line)) { auto a = sscanf(line.c_str(), "Sensor at x=%ld, y=%ld: closest beacon is at x=%ld, y=%ld", &px, &py, &bx, &by); long power = std::abs(px - bx) + std::abs(py - by); sensors.emplace_back(px, py, power); - } while (1); - - std::cout << "# of sensors: " << sensors.size() << std::endl; - - for (long y = 0; y <= 4000000; ++y) { - std::cout << "\r \r" << y; - fflush(stdout); - for (long x = 0; x <= 4000000; ++x) { - bool h = false; - - for (auto& s : sensors) { - auto dist = std::abs(x - s.x) + std::abs(y - s.y); - if (dist <= s.power) { - long spr = (dist - std::abs(s.y - y)); - x += spr - std::abs(s.x - x); - h = true; - break; - } + } + + for (auto& s : sensors) { + for (long q = 0; q <= (s.power + 1) * 2; ++q) { + auto x = s.x + q - s.power - 1; + auto y = s.y + q; + if (isDistressBeacon(Sensor(x, y))) { + std::cout << x * 4000000 + y << std::endl; + return 0; } - if (!h) { - std::cout << std::endl << x << ", " << y << std::endl; + y -= q * 2; + if (isDistressBeacon(Sensor(x, y))) { + std::cout << x * 4000000 + y << std::endl; return 0; } } |