stations.cpp: In function 'void DFS(std::vector<std::vector<int> >, int, int, int)':
stations.cpp:11:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
11 | for(int i=0; i<a[y].size(); i++){
| ~^~~~~~~~~~~~
stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:37:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
37 | for(int i=1; i<c.size()-1; i++){
| ~^~~~~~~~~~~
stations.cpp:44:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
44 | for(int i=1; i<c.size()-1; i++){
| ~^~~~~~~~~~~
stations.cpp:50:1: warning: control reaches end of non-void function [-Wreturn-type]
50 | }
| ^