stations.cpp: In function 'void dfs(int, int)':
stations.cpp:15:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
15 | for(i=0;i<g[x].size();i++){
| ~^~~~~~~~~~~~
stations.cpp: In function 'vi label(int, int, vi, vi)':
stations.cpp:28:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
28 | for(int i=0;i<u.size();i++){
| ~^~~~~~~~~
stations.cpp: In function 'int find_next_station(int, int, vi)':
stations.cpp:40:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
40 | for(i=0;i<c.size();i++){
| ~^~~~~~~~~