data structure used to implement UNDO and REDO option

Question

I want to implement UNDO and REDO option(as we see in MS word etc). Can you suggest me a data structure for it, and how can i implement it.?

Answer 1

Actually, the standard pattern for this functionality (Gang of Four, even) is Memento.

Also, while most programs use Undo/Redo stacks, afficionados of certain text editors prefer Undo/Redo trees so that they don't lose their entire history if they undo a few commands, try a new one, and change their minds.