stations.cpp: In function 'std::vector<int> label(int, int, std::vector<int>, std::vector<int>)':
stations.cpp:21:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
21 | for(int i=0;i<u.size();i++){
| ~^~~~~~~~~
stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:35:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
35 | for(int i=0;i<c.size();i++){
| ~^~~~~~~~~
stations.cpp:40:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
40 | for(int i=0;i<c.size();i++){
| ~^~~~~~~~~
stations.cpp:43:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
43 | for(int i=0;i<c.size();i++){
| ~^~~~~~~~~
stations.cpp:30:9: warning: unused variable 'n' [-Wunused-variable]
30 | int n=c.size();
| ^