Compilare: user.cpp: In function ‘int main()’: user.cpp:15:15: warning: unused variable ‘j’ [-Wunused-variable] int n,m,i,j,k,l,a,b,c; ^ user.cpp:15:17: warning: unused variable ‘k’ [-Wunused-variable] int n,m,i,j,k,l,a,b,c; ^ user.cpp:15:19: warning: unused variable ‘l’ [-Wunused-variable] int n,m,i,j,k,l,a,b,c; ^