diff options
Diffstat (limited to 'day16')
| -rw-r--r-- | day16/part1.clj | 67 | ||||
| -rw-r--r-- | day16/part2.cpp | 131 |
2 files changed, 0 insertions, 198 deletions
diff --git a/day16/part1.clj b/day16/part1.clj deleted file mode 100644 index 2358e59..0000000 --- a/day16/part1.clj +++ /dev/null @@ -1,67 +0,0 @@ -(require '[clojure.string :as str]) -(require '[clojure.set :as set]) - -(def hex-lookup - {\0 "0000" \1 "0001" \2 "0010" \3 "0011" - \4 "0100" \5 "0101" \6 "0110" \7 "0111" - \8 "1000" \9 "1001" \A "1010" \B "1011" - \C "1100" \D "1101" \E "1110" \F "1111"}) - -(defn binary-to-num [binstr] - (reduce - #(cond-> %1 true (* 2) (= \1 %2) inc) - 0 - binstr)) - -(defn take-packet-version [packet] - (-> (split-at 3 packet) - (update 0 binary-to-num))) - -(defn take-literal-value [packet] - (let [[tid data] (split-at 3 packet)] - (when (= '(\1 \0 \0) tid) - (let [sd (into [] data) - spl (split-with #(= \1 (first %)) (partition 5 sd)) - nums (map rest (concat (first spl) (take 1 (second spl))))] - [(binary-to-num (reduce concat nums)) - (drop (* 5 (inc (count (first spl)))) sd)] - )))) - -(defn take-operator [packet] - (let [id (first packet) ps (str/join (rest packet))] - (if (= \0 id) - (let [bits (binary-to-num (subs ps 0 15))] - [(subs ps 15) bits :bits]) - (let [pkts (binary-to-num (subs ps 0 11))] - [(subs ps 11) pkts :pkts])))) - -(defn process-packet [[input vcnt]] - (let [[version data] (take-packet-version input)] - (if (every? #(= \0 %) data) - ['() vcnt] - (do - (if-let [value (take-literal-value data)] - [(second value) (+ vcnt version)] - (do - (let [info (take-operator (drop 3 data))] - (if (= :bits (get info 2)) - (loop [inpt [(subs (first info) 0 (get info 1)) (+ vcnt version)]] - (if (empty? (first inpt)) - [(subs (first info) (get info 1)) (second inpt)] - (recur (process-packet inpt)))) - (loop [n (get info 1) inpt [(get info 0) (+ vcnt version)]] - (if (pos? n) - (recur (dec n) (process-packet inpt)) - inpt)))))))))) - -(loop [packet (->> (slurp "./in") - (map hex-lookup) - (take-while some?) - (reduce concat) - (str/join) - (#(vector % 0)) - (process-packet))] - (if (not (empty? (first packet))) - (recur (process-packet packet)) - (println (second packet)))) - diff --git a/day16/part2.cpp b/day16/part2.cpp deleted file mode 100644 index 5a02df9..0000000 --- a/day16/part2.cpp +++ /dev/null @@ -1,131 +0,0 @@ -#include <algorithm> -#include <cstdint> -#include <iostream> -#include <list> -#include <map> -#include <string> -#include <string_view> -#include <tuple> - -static const std::map<char, const char *> hexToBin = { - {'0', "0000"}, {'1', "0001"}, {'2', "0010"}, {'3', "0011"}, - {'4', "0100"}, {'5', "0101"}, {'6', "0110"}, {'7', "0111"}, - {'8', "1000"}, {'9', "1001"}, {'A', "1010"}, {'B', "1011"}, - {'C', "1100"}, {'D', "1101"}, {'E', "1110"}, {'F', "1111"} -}; - -static std::pair<uint64_t, std::string_view> solve(std::string_view packet); - -int main(int argc, const char *argv[]) -{ - if (argc != 2) - return -1; - - std::string packetBin; - std::string packetHex (argv[1]); - for (char c : packetHex) - packetBin += hexToBin.at(c); - - std::cout << solve(packetBin).first << std::endl; - - return 0; -} - -uint64_t binStrToInt(std::string_view bin) -{ - uint64_t n = 0; - - for (char c : bin) { - n = n * 2ull; - if (c == '1') - ++n; - } - - return n; -} - -bool isEmptyPacket(std::string_view packet) -{ - return packet.empty() || - std::all_of(packet.cbegin(), packet.cend(), - [](char c) { return c == '0'; }); -} - -std::pair<uint64_t, std::string_view> solve(std::string_view packet) -{ - // Remove version - packet = packet.substr(3); - // Pull type ID - const auto typeId = packet.substr(0, 3); - packet = packet.substr(3); - - if (typeId == "100") { - std::string numberStr; - while (1) { - const auto chunk = packet.substr(0, 5); - packet = packet.substr(5); - numberStr += chunk.substr(1); - if (chunk.front() == '0') - break; - } - - return {binStrToInt(numberStr), isEmptyPacket(packet) ? "" : packet}; - } else { - const bool isLengthBits = packet.front() == '0'; - packet = packet.substr(1); - const auto lengthStr = packet.substr(0, isLengthBits ? 15 : 11); - const auto length = binStrToInt(lengthStr); - packet = packet.substr(isLengthBits ? 15 : 11); - - std::list<uint64_t> args; - if (isLengthBits) { - auto rem = packet.substr(0, length); - while (1) { - const auto ret = solve(rem); - args.emplace_front(ret.first); - if (ret.second.empty() || isEmptyPacket(ret.second)) - break; - rem = ret.second; - } - packet = packet.substr(length); - } else { - for (uint64_t i = 0; i < length; ++i) { - const auto ret = solve(packet); - args.emplace_front(ret.first); - packet = ret.second; - if (isEmptyPacket(packet)) - break; - } - } - - uint64_t result; - if (typeId == "000") { - result = 0; - for (auto a : args) - result += a; - } else if (typeId == "001") { - result = 1; - for (auto a : args) - result *= a; - } else if (typeId == "010") { - result = *std::min_element(args.cbegin(), args.cend()); - } else if (typeId == "011") { - result = *std::max_element(args.cbegin(), args.cend()); - } else if (typeId == "101") { - const auto a1 = args.back(); - args.pop_back(); - result = args.back() < a1; - } else if (typeId == "110") { - const auto a1 = args.back(); - args.pop_back(); - result = args.back() > a1; - } else if (typeId == "111") { - const auto a1 = args.back(); - args.pop_back(); - result = args.back() == a1; - } - - return {result, isEmptyPacket(packet) ? "" : packet}; - } -} - |