/in/foo.cc: In function 'int main()':
/in/foo.cc:31:16: warning: 'p' may be used uninitialized in this function [-Wmaybe-uninitialized]
         p->next=NULL;
                ^
/in/foo.cc:15:15: note: 'p' was declared here
         Node* p;
               ^
/in/foo.cc:51:16: warning: 'p' may be used uninitialized in this function [-Wmaybe-uninitialized]
         p->next=NULL;
                ^
/in/foo.cc:35:15: note: 'p' was declared here
         Node* p;
               ^