stations.cpp: In function 'void dfs(int, int)':
stations.cpp:16:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
16 | for(int i = 0 ; i< gr[x].size() ; i++){
| ~^~~~~~~~~~~~~~
stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:47:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
47 | for(int i = 0 ; i < c.size() - 1 ; i++){
| ~~^~~~~~~~~~~~~~
stations.cpp:58:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
58 | for(int i = 1 ; i < c.size() - 1 ; i++){
| ~~^~~~~~~~~~~~~~
stations.cpp:44:16: warning: unused variable 'erg' [-Wunused-variable]
44 | int be , en , erg = -1;
| ^~~