stations.cpp: In function 'void dfs(int, int, int)':
stations.cpp:11:18: 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<v[x].size();i++){
| ~^~~~~~~~~~~~
stations.cpp: In function 'std::vector<int> label(int, int, std::vector<int>, std::vector<int>)':
stations.cpp:36:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
36 | for(int i=0;i<w.size();i++){
| ~^~~~~~~~~
stations.cpp:37:38: warning: division by zero [-Wdiv-by-zero]
37 | if(w[i]<0 or w[i]>2*n)cout<<1/0;
| ~^~
stations.cpp:41:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
41 | for(int i=0;i<sol.size();i++)sol[i]=to[sol[i]];
| ~^~~~~~~~~~~
stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:49:22: 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:55:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
55 | for(int i=0;i<c.size()-1;i++){
| ~^~~~~~~~~~~
stations.cpp:67:1: warning: control reaches end of non-void function [-Wreturn-type]
67 | }
| ^