Compilare: user.cpp: In function ‘void afisare()’: user.cpp:23:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<a[i].size();j++) ^ user.cpp: In function ‘void er(int, int)’: user.cpp:83:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<a[i].size();j++) ^ user.cpp:89:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<a[i].size();j++) ^