Compilare: main.cpp: In function 'int main()': main.cpp:28:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 28 | for (int i = 0; k <= paranthesis.size(); ++i) { | ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp:31:44: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 31 | if (longest_string_length < sub_paranthesis.size()) { | ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~