Compilare: user.cpp: In function ‘int main()’: user.cpp:19:12: warning: unused variable ‘ca’ [-Wunused-variable] {int a,b,c,ca,cb,r,x,y,d,i,n; ^ user.cpp:19:15: warning: unused variable ‘cb’ [-Wunused-variable] {int a,b,c,ca,cb,r,x,y,d,i,n; ^ user.cpp:19:18: warning: unused variable ‘r’ [-Wunused-variable] {int a,b,c,ca,cb,r,x,y,d,i,n; ^