dir.cpp: In function `bool cmp(std::vector<char, std::allocator<char> >, std::vector<char, std::allocator<char> >)': dir.cpp:13: warning: comparison between signed and unsigned integer expressions dir.cpp:13: warning: comparison between signed and unsigned integer expressions dir.cpp: In function `int main()': dir.cpp:51: warning: long int format, size_t arg (arg 2) dir.cpp:52: warning: comparison between signed and unsigned integer expressions dir.cpp:54: warning: comparison between signed and unsigned integer expressions /tmp/cc69OfDH.o(.text+0xc2): In function `main': : the `gets' function is dangerous and should not be used.