Compilare: main.cpp: In function 'int main()': main.cpp:26:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | for (int i = 0; i < s.size() - 1; ++i) { | ~~^~~~~~~~~~~~~~ main.cpp:30:72: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 30 | while (paranteza_din_dreapta >= 0 && paranteza_din_dreapta < s.size() && is_ok(s[paranteza_din_stanga], s[paranteza_din_dreapta])) { | ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~