Compilare: main.cpp: In function 'int main()': main.cpp:32:25: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 32 | if(s.size() >= l && s.size() <= u) { | ~~~~~~~~~^~~~ main.cpp:32:42: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 32 | if(s.size() >= l && s.size() <= u) { | ~~~~~~~~~^~~~ main.cpp:36:25: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 36 | if(s.size() > u) { | ~~~~~~~~~^~~