Compilare: main.cpp: In function 'bool checkVars(std::string&, std::string&)': main.cpp:58:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 58 | for (int j=0; j<a.size(); ++j) { | ~^~~~~~~~~ main.cpp:61:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 61 | for (int j=0; j<b.size(); ++j) { | ~^~~~~~~~~ main.cpp:72:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 72 | for (int j=0; j<a.size(); ++j) { | ~^~~~~~~~~ main.cpp:75:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 75 | for (int j=0; j<b.size(); ++j) { | ~^~~~~~~~~