Compilare: main.cpp: In function 'int valid(int)': main.cpp:31:9: warning: unused variable 'ok' [-Wunused-variable] int ok=1; ^~ main.cpp:48:9: warning: unused variable 'p1' [-Wunused-variable] int p1=0,p2=0; ^~ main.cpp:48:14: warning: unused variable 'p2' [-Wunused-variable] int p1=0,p2=0; ^~ main.cpp:56:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^