Compilare: user.cpp: In function ‘int main()’: user.cpp:47:52: warning: operation on ‘n’ may be undefined [-Wsequence-point] while((n<k)&&(a[n]+a[n-1]<ma))a[++n]=a[n-1]+a[n-2]; ^ user.cpp:47:52: warning: operation on ‘n’ may be undefined [-Wsequence-point] user.cpp:43:15: warning: unused variable ‘y’ [-Wunused-variable] long long i,x,y,z; ^ user.cpp:43:17: warning: unused variable ‘z’ [-Wunused-variable] long long i,x,y,z; ^