Compilare: main.cpp: In function 'int main()': main.cpp:18:10: warning: unused variable 'last' [-Wunused-variable] int n,i,last,x,m,l,j; ^~~~ main.cpp:4:11: warning: unused variable 'first' [-Wunused-variable] #define x first ^ main.cpp:18:15: note: in expansion of macro 'x' int n,i,last,x,m,l,j; ^