Eroare de compilare: user.cpp: In function 'void df(int)': user.cpp:25: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'void append(std::vector<int, std::allocator<int> >&, std::vector<int, std::allocator<int> >&)': user.cpp:49: error: 'reverse' was not declared in this scope user.cpp:51: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'int main()': user.cpp:79: warning: unused variable 'size' user.cpp:89: warning: comparison between signed and unsigned integer expressions user.cpp:92: warning: comparison between signed and unsigned integer expressions