Compilare: main.cpp: In function 'void bck(int&, std::vector<double>&, std::vector<bool>&, std::vector<int>&)': main.cpp:15:16: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 15 | if(r.size()==k) | ~~~~~~~~^~~ main.cpp:23:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<double>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 23 | for(int i=0; i<v.size(); ++i)if(!viz[i]) | ~^~~~~~~~~