Compilare: main.cpp: In function 'void back(int)': main.cpp:14:17: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 14 | if (v.size()==k) | ~~~~~~~~^~~ main.cpp:16:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 16 | for (int i = 0; i < v.size(); i++) | ~~^~~~~~~~~~