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#include <algorithm>
#include <fstream>
#include <iostream>
#include <limits>
#include <map>
#include <sstream>
#include <string>
#include <tuple>
#include <vector>
using namespace std;
auto
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;
}
auto
read_file(string_view filename)
{
fstream input{ filename };
map<string, map<string, long>> distances;
for ( string line; getline(input, line); ) {
const auto parts = split(line, ' ');
distances[parts[0]][parts[2]] = stol(parts[4]);
distances[parts[2]][parts[0]] = stol(parts[4]);
}
return distances;
}
void
part1(map<string, map<string, long>>& distances)
{
vector<string> vertex;
vertex.reserve(distances.size());
for ( const auto& iter: distances ) {
vertex.emplace_back(iter.first);
}
long min_path = numeric_limits<long>::max();
do {
long current_min_path = 0;
auto start = vertex[0];
for ( const auto& ver: vertex ) {
current_min_path += distances[start][ver];
start = ver;
}
min_path = min(min_path, current_min_path);
} while ( next_permutation(begin(vertex), end(vertex)) );
cout << min_path << endl;
}
void
part2(map<string, map<string, long>>& distances)
{
vector<string> vertex;
vertex.reserve(distances.size());
for ( const auto& iter: distances ) {
vertex.emplace_back(iter.first);
}
long max_path = numeric_limits<long>::min();
do {
long current_max_path = 0;
auto start = vertex[0];
for ( const auto& ver: vertex ) {
current_max_path += distances[start][ver];
start = ver;
}
max_path = max(max_path, current_max_path);
} while ( next_permutation(begin(vertex), end(vertex)) );
cout << max_path << endl;
}
int
main()
{
auto distances = read_file("data/day09.txt");
part1(distances);
part2(distances);
}
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