Compilare: user.cpp:147:2: warning: no newline at end of file user.cpp: In function 'void df(int)': user.cpp:40: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'int find(int, int)': user.cpp:76: warning: operation on 'x' may be undefined user.cpp: In function 'int main()': user.cpp:142: warning: operation on 'x' may be undefined