Compilare: user.cpp: In function 'void bf(int)': user.cpp:38: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'int df(int, int)': user.cpp:62: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'int solve(int, int, int)': user.cpp:78: warning: comparison between signed and unsigned integer expressions user.cpp:91: warning: control reaches end of non-void function user.cpp: In function 'int df(int, int)': user.cpp:71: warning: control reaches end of non-void function