c++ - Lexixal or Preprocessor issue: 'iostream' file not found -

c++ - Lexixal or Preprocessor issue: 'iostream' file not found -

i trying utilize qqwing.h, qqwing.cpp , config.h files in project create sudoku game , getting below error.

i tried lot of solutions changing , setting different values in project nil has solved issue.

please help!

c++ objective-c xcode5 sudoku qqwing