stations.cpp: In function 'void dfs(int, int)':
stations.cpp:18:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
18 | for (int i = 0; i < g[node].size(); ++i)
| ~~^~~~~~~~~~~~~~~~
stations.cpp: In function 'std::vector<int> label(int, int, std::vector<int>, std::vector<int>)':
stations.cpp:31:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
31 | for (int i = 0; i < u.size(); ++i)
| ~~^~~~~~~~~~
stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:62:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
62 | for (int i = 0; i < c.size(); ++i)
| ~~^~~~~~~~~~
stations.cpp:75:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
75 | for (int i = 0; i < c.size(); ++i)
| ~~^~~~~~~~~~