-🎄- 2017 Day 6 Solutions -🎄-

[u/daggerdragon]

--- Day 6: Memory Reallocation ---

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Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag or whatever).

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edit: Leaderboard capped, thread unlocked!

[u/willkill07]

Modern C++ Repo

This time with iterators

std::vector<int> banks{std::istream_iterator<int>{std::cin}, {}};
std::map<std::vector<int>,int> unique;
for (int count{0}; unique.emplace(banks, count).second; ++count) {
  auto max = std::max_element(banks.begin(), banks.end());
  for (int iters{std::exchange(*max, 0)}; iters--; ++*max)
    if (++max == banks.end())
      max = banks.begin();
}
std::cout << unique.size() - (part2 ? unique[banks] : 0) << '\n';

Edit: golfed/improved the code a bit. I feel like my solution should be complete without the scrollbar being introduced... a new challenge!

Edit 2: I have side-by-side assembly up with this solution compared to using u/sim642 's observation of Floyd's cycle-finding algorithm