Compilare: main.cpp: In function 'void Back(std::vector<int>&, int, std::vector<int>&)': main.cpp:45:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 45 | for(int i = sub[k-1] + 1; i < elem.size(); i++) | ~~^~~~~~~~~~~~~ main.cpp:49:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 49 | if(k < elem.size()) | ~~^~~~~~~~~~~~~