Compilare: user.cpp: In function 'int query(NodT*, char*)': user.cpp:27: warning: array subscript has type 'char' user.cpp: In function 'int del(NodT*, char*)': user.cpp:35: warning: array subscript has type 'char' user.cpp:37: warning: array subscript has type 'char' user.cpp: In function 'int insert(NodT*, char*)': user.cpp:53: warning: array subscript has type 'char' user.cpp:55: warning: array subscript has type 'char' user.cpp:58: warning: array subscript has type 'char' user.cpp:60: warning: control reaches end of non-void function