dango3.cpp: In function 'void solve(int, std::vector<int>)':
dango3.cpp:8:16: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
    8 |     if(V.size()==N) {
      |        ~~~~~~~~^~~
dango3.cpp:21:17: warning: unused variable 'n' [-Wunused-variable]
   21 |         for(int n : V1) V.pop_back();
      |                 ^
dango3.cpp:14:9: warning: unused variable 'i' [-Wunused-variable]
   14 |     int i, j;
      |         ^
dango3.cpp:14:12: warning: unused variable 'j' [-Wunused-variable]
   14 |     int i, j;
      |            ^
dango3.cpp: In function 'void Solve(int, int)':
dango3.cpp:31:12: warning: unused variable 'j' [-Wunused-variable]
   31 |     int i, j;
      |            ^