From b92a50d54677abfcf63e216dc5982896a83690d2 Mon Sep 17 00:00:00 2001
From: Eric Mertens <emertens@galois.com>
Date: Sat, 28 Jan 2023 08:39:08 -0800
Subject: [PATCH] wip 2022-16

---
 2022/16.cpp         | 166 ++++++++++++++++++++++++++++++++++++++++++++
 2022/CMakeLists.txt |   3 +
 2 files changed, 169 insertions(+)
 create mode 100644 2022/16.cpp

diff --git a/2022/16.cpp b/2022/16.cpp
new file mode 100644
index 0000000..44bd9bd
--- /dev/null
+++ b/2022/16.cpp
@@ -0,0 +1,166 @@
+#include <cstdint>
+#include <iostream>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+#include <tuple>
+#include <vector>
+#include <map>
+#include <bitset>
+
+#include <boost/spirit/home/qi.hpp>
+#include <boost/range/irange.hpp>
+
+#include <doctest.h>
+
+#include <aocpp/Startup.hpp>
+
+namespace {
+
+auto ShortestDistances(std::vector<std::vector<std::uint64_t>> & dist)
+{
+  auto const range = boost::irange(dist.size());
+  for (auto const k : range) {
+    for (auto const i : range) {
+      for (auto const j : range) {
+        auto const new_dist = dist[i][k] + dist[k][j];
+        auto & old_dist = dist[i][j];
+        if (old_dist > new_dist) old_dist = new_dist;
+      }
+    }
+  }
+}
+
+struct RawRoom {
+  std::string name;
+  std::uint64_t flow;
+  std::vector<std::string> connections;
+};
+
+struct Room {
+  std::uint64_t flow;
+  std::vector<std::uint64_t> connections;
+};
+
+auto Parse(std::istream & in) -> std::vector<RawRoom>
+{
+  std::vector<RawRoom> result;
+  std::string line;
+  while (std::getline(in, line)) {
+    RawRoom room;
+    using namespace boost::spirit;
+    auto const name = qi::as_string[+qi::alpha];
+    auto const room_description =
+      "Valve " >>
+      name [ ([&](auto n) { room.name = n; }) ] >>
+      " has flow rate=" >>
+      qi::ulong_long [ ([&](auto f) { room.flow = f; }) ] >>
+      "; tunnel"  >> -qi::string("s") >>
+      " lead"     >> -qi::string("s") >>
+      " to valve" >> -qi::string("s") >>
+      " " >>
+      (name % ", ") [ ([&](auto c) { room.connections = c; }) ];
+
+    if (!qi::parse(line.begin(), line.end(), room_description)) {
+      throw std::runtime_error{"bad input line"};
+    }
+    result.emplace_back(std::move(room));
+  }
+  return result;
+}
+
+auto GenerateGraph(std::vector<RawRoom> const& raw_rooms) -> std::vector<Room>
+{
+  std::vector<Room> result;
+  std::map<std::string, std::size_t> names;
+
+  std::vector<std::vector<std::uint64_t>> distances(
+    raw_rooms.size(), std::vector<std::uint64_t>(raw_rooms.size(), 100)); // todo max limit
+  
+  for (auto const i : boost::irange(raw_rooms.size())) {
+    names[raw_rooms[i].name] = i;
+  }
+
+  for (auto const i : boost::irange(raw_rooms.size())) {
+    auto & ds = distances[i];
+    for (auto const& name : raw_rooms[i].connections) {
+      ds[names[name]] = 1;
+    }
+  }
+
+  ShortestDistances(distances);
+
+  for (auto const i : boost::irange(raw_rooms.size())) {
+    result.push_back({raw_rooms[i].flow, std::move(distances[i])});
+  }
+
+  return result;
+}
+
+using Valves = std::bitset<64>;
+
+struct State {
+  std::uint64_t time;
+  std::uint64_t flow;
+  std::size_t location;
+  Valves valves;
+};
+
+auto Routes(std::vector<Room> const& rooms, std::uint64_t time) -> std::map<unsigned long long, std::uint64_t>
+{
+  std::vector<State> states { State{time, 0, 0, {}} };
+  std::map<unsigned long long, std::uint64_t> result;
+  
+  while (!states.empty()) {
+    auto state = states.back();
+    states.pop_back();
+
+    auto const& room = rooms[state.location];
+
+    for (auto const i : boost::irange(rooms.size())) {
+      auto valves = state.valves;
+      if (valves[i]) { continue; }
+      auto const flow = rooms[i].flow;
+      if (flow == 0) { continue; }
+      auto const cost = room.connections[i];
+      if (cost >= state.time) { continue; }
+      auto const time_ = state.time - cost - 1;
+      
+      valves[i] = true;
+      auto const flow_ = state.flow + time_;
+
+      if (result[valves.to_ullong()] < flow_) {
+        result[valves.to_ullong()] = flow_;
+      }
+
+      states.push_back({ time_, state.flow + time_, i, valves});
+    }
+  }
+  
+  return result;
+}
+
+} // namespace
+
+TEST_SUITE("2022-16 examples") {
+  TEST_CASE("example") {
+    std::istringstream in {
+ 
+    };
+  }
+}
+
+auto main(int argc, char** argv) -> int
+{
+  auto const input = Parse(*aocpp::Startup(argc, argv));
+  auto const graph = GenerateGraph(input);
+  auto const routes = Routes(graph, 30);
+  
+  std::uint64_t p1 = 0;
+  for (auto const& kv : routes) {
+    p1 = std::max(p1, kv.second);
+  }
+
+  std::cout << "Part 1: " << p1 << std::endl;
+  //Part2(snapshots, std::cout << "Part 2:\n");
+}
diff --git a/2022/CMakeLists.txt b/2022/CMakeLists.txt
index 0a790ac..d9b40c0 100644
--- a/2022/CMakeLists.txt
+++ b/2022/CMakeLists.txt
@@ -31,6 +31,9 @@ target_link_libraries(2022_12 aocpp)
 add_executable(2022_13 13.cpp)
 target_link_libraries(2022_13 aocpp)
 
+add_executable(2022_16 16.cpp)
+target_link_libraries(2022_16 aocpp Boost::headers)
+
 add_executable(2022_18 18.cpp)
 target_link_libraries(2022_18 aocpp)