cpp_diary it's an assignment of OOP. input standard 1.pdadd: week4.exe pdadd date(Y M D: like 2018/04/28 or 2018.04.28 whatever it is, just keep it consistent) 2.pdlist(2 ways are supported): (1) week4.exe pdlist (2) week4.exe pdlist date_begin date_end 3.pdshow: week4.exe pdshow date 4.pdremove: week4.exe pdremove date