Compilare: user.cpp: In function ‘void cer2()’: user.cpp:28:60: warning: operation on ‘n’ may be undefined [-Wsequence-point] while((n<k)&&(a[n]+a[n-1]<INT_MAX))a[++n]=a[n-1]+a[n-2]; ^ user.cpp:28:60: warning: operation on ‘n’ may be undefined [-Wsequence-point] user.cpp:25:19: warning: unused variable ‘y’ [-Wunused-variable] long long i,x,y,z; ^ user.cpp:25:21: warning: unused variable ‘z’ [-Wunused-variable] long long i,x,y,z; ^