Compilare: main.cpp: In function 'int main()': main.cpp:29:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(!s.empty() && i < strlen(mainString)) ~~^~~~~~~~~~~~~~~~~~~~ main.cpp:32:89: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(mainString[i] != '(' && mainString[i] != ',' && mainString[i] != ')' && i < strlen(mainString)) ~~^~~~~~~~~~~~~~~~~~~~