Compilare: user.cpp: In function ‘int main()’: user.cpp:8:17: warning: unused variable ‘r’ [-Wunused-variable] int n,i,x,y,r,nr=0,a,b,j; ^ user.cpp:8:24: warning: unused variable ‘a’ [-Wunused-variable] int n,i,x,y,r,nr=0,a,b,j; ^ user.cpp:8:26: warning: unused variable ‘b’ [-Wunused-variable] int n,i,x,y,r,nr=0,a,b,j; ^