C++菜鸟请教个错误是为什么？如何改正？感谢！！

C:\Users\dell\Desktop\execisiii\0.cpp|13|error: field 'w' has incomplete type|
C:\Users\dell\Desktop\execisiii\0.cpp||In member function 'void s::set()':|
C:\Users\dell\Desktop\execisiii\0.cpp|21|error: 'w' was not declared in this scope|
C:\Users\dell\Desktop\execisiii\0.cpp|22|error: 'W' was not declared in this scope|
C:\Users\dell\Desktop\execisiii\0.cpp||In member function 'void s::show()':|
C:\Users\dell\Desktop\execisiii\0.cpp|29|error: 'w' was not declared in this scope|
||=== Build failed: 4 error(s), 0 warning(s) (0 minute(s), 1 second(s)) ===|

图太小了根本看不清，你直接把源代码贴出来呗