Compilare: user.cpp: In function ‘int main()’: user.cpp:11:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i=1; i<=n; i++ ) ^ user.cpp:13:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i=1; i<=n; i++ ) ^ user.cpp:17:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i=1; i<=n; i++ ) ^