stations.cpp: In function 'void dfs(int)':
stations.cpp:9:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
9 | for(int i=0;i<adj[v].size();i++)
| ~^~~~~~~~~~~~~~
stations.cpp: In function 'std::vector<int> label(int, int, std::vector<int>, std::vector<int>)':
stations.cpp:23:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
23 | for(int i=0;i<u.size();i++)
| ~^~~~~~~~~
stations.cpp:29:34: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
29 | for(int i=0;i<n;i++)if(!vis[i])for(;;);
| ^~~
stations.cpp:30:5: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
30 | vector<int>ans;
| ^~~~~~
stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:40:14: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
40 | if(cc<=aa&&bb<=dd||bb<cc||dd<aa)
| ~~~~~~^~~~~~~~
stations.cpp:42:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
42 | for(int i=0;i<c.size();i++)
| ~^~~~~~~~~
stations.cpp:49:18: 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:55:1: warning: control reaches end of non-void function [-Wreturn-type]
55 | }
| ^