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#include <fstream>
#include <iostream>
#include <sstream>
#include <unordered_map>
#include <vector>
#include <numeric>
#include "util.h"
using Pos = std::string;
using Moves = std::vector<bool>;
using Map = std::unordered_map<Pos,std::pair<Pos,Pos>>;
constexpr char EQUAL[] = "=";
std::pair<Moves,Map> parse(const char* path)
{
Map map{};
Moves moves{};
std::ifstream input{ path };
if (input.is_open())
{
std::string line;
std::getline(input,line);
moves.resize(line.size());
std::transform(line.cbegin(), line.cend(),
moves.begin(), [](unsigned char c) { return c == 'L'; });
std::string from, tol, tor;
while (not std::getline(input,line).eof())
{
if (line.empty()) continue;
std::istringstream in{ line };
in >> from >> util::skip<EQUAL> >> tol >> tor;
tol.erase(0,1); tol.pop_back();
tor.pop_back();
map.insert({ from, { tol, tor } });
}
}
input.close();
return { std::move(moves), std::move(map) };
}
long long compute(const Map& map, const Moves& moves, Pos pos)
{
long long idx{};
while (pos[2] != 'Z')
{
bool left = moves[idx++ % moves.size()];
pos = left ? map.at(pos).first : map.at(pos).second;
}
return idx;
}
int main(int argc, char* argv[])
{
long long answer{ 1 };
auto [moves, map] = parse(argv[1]);
for (const auto& kv : map)
{
if (kv.first[2] == 'A')
{
answer = std::lcm(answer, compute(map, moves, kv.first));
}
}
std::cout << answer << std::endl;
return 0;
}
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