Compilare: user.cpp: In function ‘int main()’: user.cpp:23:9: warning: unused variable ‘r’ [-Wunused-variable] int r,a,b,m,n,k,x,y,t,i; ^ user.cpp:23:11: warning: unused variable ‘a’ [-Wunused-variable] int r,a,b,m,n,k,x,y,t,i; ^ user.cpp:23:13: warning: unused variable ‘b’ [-Wunused-variable] int r,a,b,m,n,k,x,y,t,i; ^