Compilare: main.cpp: In function 'int getValue(std::__cxx11::string)': main.cpp:18:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 2; i < s.size(); i++) { ~~^~~~~~~~~~ main.cpp: In function 'void writeFunctionTerms(std::__cxx11::string)': main.cpp:26:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 2; i < s.size(); ++i) { ~~^~~~~~~~~~ main.cpp: In function 'int calculateBigFunction(std::__cxx11::string)': main.cpp:43:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < bigFunction.size() - 1) { ~~^~~~~~~~~~~~~~~~~~~~~~~~