Compilare: main.cpp: In function 'bool term()': main.cpp:40:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 40 | while(pos_tok < tokens.size() && tokens[pos_tok] == "AND") { | ~~~~~~~~^~~~~~~~~~~~~~~ main.cpp: In function 'bool expr()': main.cpp:50:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 50 | while(pos_tok < tokens.size() && tokens[pos_tok] == "OR") { | ~~~~~~~~^~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:67:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 67 | while(i < s.size()) { | ~~^~~~~~~~~~ main.cpp:77:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 77 | while(i < s.size() && s[i] >= 'A' && s[i] <= 'Z') { | ~~^~~~~~~~~~