Update ex12_26.cpp
Update ex12_26.cpp

Exchange the order of the  bool evaluation because there is no need to ask input if pointer q reached the end of the dynamic memory.
andersy005/Cpp-Primer,sanerror/Cpp-Primer,Soyn/Cpp-Primer,Mooophy/Cpp-Primer,Soyn/Cpp-Primer,andersy005/Cpp-Primer,Mooophy/Cpp-Primer,AndychenCL/Cpp-Primer,Squawk09/Cpp-Primer,AndychenCL/Cpp-Primer,Squawk09/Cpp-Primer,sanerror/Cpp-Primer