Compilare: user.cpp:57:2: warning: no newline at end of file user.cpp: In function 'void calc_prefix(std::string, std::vector<int, std::allocator<int> >&)': user.cpp:9: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'void find_matches(std::string, std::string, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >&)': user.cpp:20: warning: comparison between signed and unsigned integer expressions user.cpp:26: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'int main()': user.cpp:50: warning: comparison between signed and unsigned integer expressions