/in/foo.cc: In function 'Tree* Find1(int)':
/in/foo.cc:126:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'void Insert23(int, int)':
/in/foo.cc:68:44: warning: 'newone' may be used uninitialized in this function [-Wmaybe-uninitialized]
     newone->ch[0]=newone->ch[1]=newone->pre=null;
                                 ~~~~~~~~~~~^~~~~
/in/foo.cc:62:11: note: 'newone' was declared here
     Tree *newone;
           ^~~~~~