Compilare: user.cpp:34: warning: integer constant is too large for ‘long’ type user.cpp: In function ‘int exract_min()’: user.cpp:34: warning: overflow in implicit constant conversion user.cpp: In function ‘void back(int, long long int, int)’: user.cpp:60: warning: NULL used in arithmetic user.cpp: In function ‘int exract_min()’: user.cpp:34: warning: ‘p’ may be used uninitialized in this function