aoc 2016, day 10

1 files changed, 102 insertions, 0 deletions

diff --git a/2016/src/day10.cpp b/2016/src/day10.cpp
new file mode 100644
index 0000000..7c1f4f9
--- /dev/null
+++ b/2016/src/day10.cpp
@@ -0,0 +1,102 @@
+#include <fstream>
+#include <iostream>
+#include <map>
+#include <sstream>
+#include <string>
+#include <tuple>
+
+using namespace std;
+
+using Sink = tuple<string, int>;
+
+vector<string>
+split(const string& line, char sep)
+{
+        vector<string> parts;
+        stringstream   input{ line };
+
+        for ( string part; getline(input, part, sep); ) {
+                parts.emplace_back(part);
+        }
+
+        return parts;
+}
+
+map<int, tuple<Sink, Sink, vector<int>>>
+read_file(string_view filename)
+{
+        fstream input{ filename };
+
+        map<int, tuple<Sink, Sink, vector<int>>> bots;
+
+        for ( string line; getline(input, line); ) {
+                const auto parts = split(line, ' ');
+
+                if ( parts.at(0) == "bot" ) {
+                        const Sink low_sink = { parts.at(5), stoi(parts.at(6)) };
+                        const Sink hi_sink  = { parts.at(10), stoi(parts.at(11)) };
+
+                        auto& bot = bots[stoi(parts.at(1))];
+
+                        get<0>(bot) = low_sink;
+                        get<1>(bot) = hi_sink;
+                }
+                else if ( parts.at(0) == "value" ) {
+                        auto& bot = bots[stoi(parts.at(5))];
+
+                        get<2>(bot).push_back(stoi(parts.at(1)));
+                }
+        }
+
+        return bots;
+}
+
+void
+solve(map<int, tuple<Sink, Sink, vector<int>>> bots)
+{
+        map<int, int> outputs;
+
+        const auto store = [&](const Sink& sink, int value) {
+                if ( get<0>(sink) == "bot" ) {
+                        auto& to_bot = bots[get<1>(sink)];
+                        get<2>(to_bot).push_back(value);
+                }
+                else {
+                        outputs[get<1>(sink)] = value;
+                }
+        };
+
+        while ( true ) {
+                auto it = ranges::find_if(bots, [](auto& bot) {
+                        const auto& [id, values] = bot;
+                        return (get<2>(values).size() == 2);
+                });
+                if ( it == bots.end() ) {
+                        break;
+                }
+
+                auto& [id, values]               = *it;
+                auto& [low_sink, hi_sink, chips] = values;
+
+                ranges::sort(chips);
+                store(low_sink, chips.at(0));
+                store(hi_sink, chips.at(1));
+
+                // part1
+                if ( chips.at(0) == 17 && chips.at(1) == 61 ) {
+                        cout << id << endl;
+                }
+
+                chips.clear();
+        }
+
+        // part2
+        cout << outputs[0] * outputs[1] * outputs[2] << endl;
+}
+
+int
+main()
+{
+        auto bots = read_file("data/day10.txt");
+        solve(bots);
+}