stations.cpp: In function 'void dfs(int, int)':
stations.cpp:15:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
15 | for (int i=0;i<gr[x].size();i++)
| ~^~~~~~~~~~~~~
stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:49:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
49 | for (int i=0;i<c.size();i++)
| ~^~~~~~~~~
stations.cpp:57:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
57 | for (i=0;i<c.size()-1;i++)
| ~^~~~~~~~~~~
stations.cpp:72:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
72 | for (i=1;i<c.size()-1;i++)
| ~^~~~~~~~~~~