add ex12.3-6  On branch ch12 	modified:   ch12/binary_search_tree.hpp
add ex12.3-6
 On branch ch12
	modified:   ch12/binary_search_tree.hpp

Mooophy/CLRS,opensourceDA/CLRS,Mooophy/CLRS,tushar2708/CLRS,Mooophy/CLRS,tushar2708/CLRS,opensourceDA/CLRS,opensourceDA/CLRS,tushar2708/CLRS,tushar2708/CLRS,opensourceDA/CLRS,Mooophy/CLRS