Compilare: user.cpp: In function ‘int main()’: user.cpp:10:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<str.size()/2;++i) g<<str[i]; ^ user.cpp:7:24: warning: unused variable ‘n’ [-Wunused-variable] unsigned long long n,d1=0,d2=0,nr,st,dr; ^ user.cpp:7:26: warning: unused variable ‘d1’ [-Wunused-variable] unsigned long long n,d1=0,d2=0,nr,st,dr; ^ user.cpp:7:31: warning: unused variable ‘d2’ [-Wunused-variable] unsigned long long n,d1=0,d2=0,nr,st,dr; ^ user.cpp:7:36: warning: unused variable ‘nr’ [-Wunused-variable] unsigned long long n,d1=0,d2=0,nr,st,dr; ^ user.cpp:7:39: warning: unused variable ‘st’ [-Wunused-variable] unsigned long long n,d1=0,d2=0,nr,st,dr; ^ user.cpp:7:42: warning: unused variable ‘dr’ [-Wunused-variable] unsigned long long n,d1=0,d2=0,nr,st,dr; ^