Compilare: main.cpp: In function 'void prel()': main.cpp:59:13: warning: unused variable 'st' [-Wunused-variable] 59 | int st=b[i].st; | ^~ main.cpp:60:13: warning: unused variable 'dr' [-Wunused-variable] 60 | int dr=b[i].dr; | ^~ main.cpp:62:13: warning: unused variable 'nodu' [-Wunused-variable] 62 | int nodu=b[i+1].nod; | ^~~~