grad.cpp: In function 'std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > exploade(std::string)': grad.cpp:15: warning: comparison between signed and unsigned integer expressions grad.cpp: In function 'int grad(std::string)': grad.cpp:34: warning: comparison between signed and unsigned integer expressions grad.cpp: In function 'int main()': grad.cpp:46: warning: comparison between signed and unsigned integer expressions