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#include <algorithm>
#include <fstream>
#include <iostream>
#include <map>
#include <memory>
#include <queue>
#include <string>
#include <vector>
using namespace std;
vector<string>
read_file(string_view filename)
{
fstream input{ filename };
vector<string> data;
for ( string line; getline(input, line); ) {
data.emplace_back(line);
}
return data;
}
vector<string>
split(string_view line, string_view delimiter)
{
size_t pos_start = 0;
size_t pos_end = 0;
vector<string> res;
while ( (pos_end = line.find(delimiter, pos_start)) != string::npos ) {
auto token = line.substr(pos_start, pos_end - pos_start);
pos_start = pos_end + delimiter.length();
res.emplace_back(token);
}
if ( pos_start != line.size() ) {
res.emplace_back(line.substr(pos_start));
}
return res;
}
struct Module { // NOLINT
protected:
explicit Module(string_view name, queue<tuple<string, int, string>>& queue)
: name_(name)
, queue_(queue)
{
}
virtual ~Module() = default;
public:
virtual void trigger(string_view sender, int signal) = 0;
void register_sender(string_view sender) { senders_.emplace(sender, 0); }
protected:
void send_signal(int signal) const
{
for ( const auto& link: links_ ) {
queue_.emplace(name_, signal, link);
}
}
public:
void add_link(string_view link) { links_.emplace_back(link); }
protected:
const string name_;
queue<tuple<string, int, string>>& queue_;
public:
vector<string> links_;
map<string, int> senders_;
};
struct BroadcasterModuler : public Module {
explicit BroadcasterModuler(string_view name, queue<tuple<string, int, string>>& queue)
: Module(name, queue)
{
}
void trigger(string_view, int signal) override
{
send_signal(signal);
}
};
struct FlipFlopModule : public Module {
explicit FlipFlopModule(string_view name, queue<tuple<string, int, string>>& queue)
: Module(name, queue)
{
}
void trigger(string_view, int signal) override
{
if ( signal == 1 ) {
return;
}
state_ = (state_ + 1) % 2;
send_signal(state_);
}
int state_{ 0 };
};
struct ConjunctionModule : public Module {
explicit ConjunctionModule(string_view name, queue<tuple<string, int, string>>& queue)
: Module(name, queue)
{
}
void trigger(string_view sender, int signal) override
{
senders_[string(sender)] = signal;
if ( all_of(senders_.begin(), senders_.end(), [](const auto& link) { return link.second == 1; }) ) {
send_signal(0);
}
else {
send_signal(1);
}
}
};
struct OutputModule : public Module {
explicit OutputModule(string_view name, queue<tuple<string, int, string>>& queue)
: Module(name, queue)
{
}
void trigger(string_view, int) override
{
}
};
void
part1()
{
queue<tuple<string, int, string>> queue;
map<string, shared_ptr<Module>> modules;
modules["output"] = make_shared<OutputModule>("output", queue);
const auto input = read_file("data/day20.txt");
for ( const auto& line: input ) {
const auto parts = split(line, " -> ");
auto module = parts[0];
const auto dests = split(parts[1], ", ");
shared_ptr<Module> ptr;
if ( module == "broadcaster" ) {
ptr = make_shared<BroadcasterModuler>(module, queue);
}
else if ( module.starts_with('%') ) {
module.erase(0, 1);
ptr = make_shared<FlipFlopModule>(module, queue);
}
else if ( module.starts_with('&') ) {
module.erase(0, 1);
ptr = make_shared<ConjunctionModule>(module, queue);
}
else {
cerr << "unknown module type: " << module << endl;
return;
}
for ( const auto& dest: dests ) {
ptr->add_link(dest);
}
modules[module] = ptr;
}
// register senders
for ( auto& module: modules ) {
auto [name, ptr] = module;
for ( const auto& link: ptr->links_ ) {
if ( modules.contains(link) ) {
modules[link]->register_sender(name);
}
}
}
long sums[2] = { 0, 0 };
for ( int i = 0; i != 1000; ++i ) {
queue.emplace("button", 0, "broadcaster");
while ( !queue.empty() ) {
const auto [sender, signal, receiver] = queue.front();
queue.pop();
sums[signal]++;
if ( modules.contains(receiver) ) {
modules[receiver]->trigger(sender, signal);
}
}
}
cout << sums[0] * sums[1] << endl;
}
int
main()
{
part1();
}
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