Compilare: main.cpp: In function 'int32_t main()': main.cpp:72:13: warning: unused variable 'n_x1' [-Wunused-variable] int n_x1,n_y1,n_x2,n_y2; ^~~~ main.cpp:72:18: warning: unused variable 'n_y1' [-Wunused-variable] int n_x1,n_y1,n_x2,n_y2; ^~~~ main.cpp:72:23: warning: unused variable 'n_x2' [-Wunused-variable] int n_x1,n_y1,n_x2,n_y2; ^~~~ main.cpp:72:28: warning: unused variable 'n_y2' [-Wunused-variable] int n_x1,n_y1,n_x2,n_y2; ^~~~