Linker Error:undefined symbol _atoll in module vocab_count.c Turbo C++

I am trying to implement glove model and train on my own dataset following the source code on this link http://ift.tt/2uuIGLS When I am trying to run vocab_count.c in Turbo C++ application I am getting this error.

Linker Error:undefined symbol _atoll in module vocab_count.c

Line of code causing error is this

if ((i = find_arg((char *)"-max-vocab", argc, argv)) > 0) max_vocab = atoll(argv[i + 1]);
    if ((i = find_arg((char *)"-min-count", argc, argv)) > 0) min_count = atoll(argv[i + 1]);

Kindly help me resolve this. Thanks