Compilare: user.cpp: In function ‘int main()’: user.cpp:24:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( j = 0 ; j < graf[i].size() ; j++ ) ^ user.cpp:27:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( k = 0 ; k < graf[graf[i][j]].size() ; k++ ) ^