Compilare: main.cpp: In function 'int evaluate(std::string)': main.cpp:32:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 32 | for(int i = 0; i < tokens.size(); i++){ | ~~^~~~~~~~~~~~~~~ main.cpp:37:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 37 | while(i < tokens.size() && isdigit(tokens[i])){ | ~~^~~~~~~~~~~~~~~ main.cpp: In function 'int applyOp(int, int, char)': main.cpp:27:1: warning: control reaches end of non-void function [-Wreturn-type] 27 | } | ^