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: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:51:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
51 | for(int i=1; i<c.size()-1; i++){
| ~^~~~~~~~~~~
stations.cpp:39:7: warning: unused variable 'parent' [-Wunused-variable]
39 | bool parent=true;
| ^~~~~~
stations.cpp:40:6: warning: unused variable 'ans' [-Wunused-variable]
40 | int ans;
| ^~~