diff options
Diffstat (limited to 'day9/part1.cpp')
| -rw-r--r-- | day9/part1.cpp | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/day9/part1.cpp b/day9/part1.cpp index ecfbdd6..61b6f8d 100644 --- a/day9/part1.cpp +++ b/day9/part1.cpp @@ -1,6 +1,5 @@ #include <algorithm> #include <iostream> -#include <list> #include <string> #include <tuple> #include <vector> @@ -8,6 +7,7 @@ int main() { std::vector<std::pair<char, int>> steps; + std::vector<int> hashes (10000, 0); while (1) { std::string line; @@ -19,13 +19,9 @@ int main() } int hx = 0, hy = 0, tx = 0, ty = 0; - std::list<std::pair<int, int>> locs; - locs.emplace_back(0, 0); for (const auto& [dir, count] : steps) { for (int i = 0; i < count; ++i) { - //std::cout << hx << ", " << hy << " " << tx << ", " << ty << std::endl; - if (dir == 'U') ++hy; else if (dir == 'D') @@ -41,14 +37,26 @@ int main() if (hy != ty) ty += hy > ty ? 1 : -1; - if (std::find(locs.cbegin(), locs.cend(), std::pair{tx, ty}) == locs.cend()) { - locs.emplace_back(tx, ty); + int hash = tx * 1000 + ty; + for (int i = 0; i < hashes.size(); ++i) { + if (hashes[i] == 0) { + hashes[i] = hash; + break; + } else if (hashes[i] == hash) { + break; + } } } } } - std::cout << locs.size() << std::endl; + int count = 0; + for (int i = 0; i < hashes.size(); ++i) { + ++count; + if (hashes[i] == 0) + break; + } + std::cout << count << std::endl; return 0; } |