stations.cpp:9:62: error: 'std::vector<int> label(int, int, std::vector<int>, std::vector<int>)' redeclared as different kind of entity
9 | vector <int> label(int n, int k, vector<int> u, vector<int> v)
| ^
stations.cpp:7:14: note: previous declaration 'std::vector<int> label'
7 | vector <int> label;
| ^~~~~
stations.cpp: In function 'std::vector<int> label(int, int, std::vector<int>, std::vector<int>)':
stations.cpp:18:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
18 | for(i=0;i<u.size();i++)
| ~^~~~~~~~~