Compilare: user.cpp: In function 'void prefix(const std::string&, std::vector<int, std::allocator<int> >&)': user.cpp:13: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'void search(const std::string&, const std::string&, std::vector<int, std::allocator<int> >&)': user.cpp:26: warning: comparison between signed and unsigned integer expressions user.cpp:30: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'int main()': user.cpp:44: warning: comparison between signed and unsigned integer expressions