Compilare: user.cpp: In function ‘int expresie()’: user.cpp:18:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i!=a.size() && a[i]!=')'){ ^ user.cpp: In function ‘void comparare()’: user.cpp:91:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(p=0;p<a.size();p++){ ^ user.cpp:122:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(p=0;p<a.size();p++){ ^