Compilare: main.cpp: In function 'int expr()': main.cpp:18:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (poz < sir.size()) ~~~~^~~~~~~~~~~~ main.cpp: In function 'int termen()': main.cpp:39:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (poz < sir.size()) ~~~~^~~~~~~~~~~~ main.cpp: In function 'int factor()': main.cpp:68:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (poz < sir.size() && '0' <= sir[poz] && sir[poz] <= '9') ~~~~^~~~~~~~~~~~