Compilare: main.cpp: In function 'void calcExp(bool, bool, int, int)': main.cpp:21:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos < cod.size() && '0' <= cod[pos] && cod[pos] <= '9') ~~~~^~~~~~~~~~~~ main.cpp:41:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos < cod.size() && '0' <= cod[pos] && cod[pos] <= '9') ~~~~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:74:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < cod.size(); i++) ~~^~~~~~~~~~~~