advent-of-code/2023/8/main-1.cpp

#include <bits/stdc++.h>
using namespace std;

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

	string instructions;
	getline(cin, instructions);
	cin.ignore(1);

	unordered_map<string, pair<string, string>> locs;

	string line;
	while (getline(cin, line)) {
		locs[line.substr(0, 3)] = make_pair(line.substr(7, 3), line.substr(12, 3));
	}

	string current = "AAA";
	int i = 0;
	while (current != "ZZZ") {
		if (instructions[i++ % instructions.length()] == 'L')
			current = locs[current].first;
		else
			current = locs[current].second;
	}

	cout << i << '\n';
}