$1.$ Instructions

Create a C$++$ program that utilizes a stack to simulate a text editor$$s $$Undo$$ Function. You

MUST use stacks in your implementation. You may use the standard library stack.

$2.$ Input Files

$$ The input file will contain multiple commands, representing modifications made to the

string, separated by an endl.

$$ Insert $$text$->$ appends $$text$$ to the output string

$$ Delete $$text$->$ deletes $$text$,$ which will always be a unique substring, from the

output string.

$$ Undo $->$ Reverts the previous command

Note: All possible warnings may not be given. If you think of an edge case, cover it in your code.

$3.$ Output Files

$$ Output the string at the end of your program$$s execution.

$$ Account for spaces between every inserted string. Notice there are no spaces at the

beginning or end.

$4.$ Examples

input$1.$txt

Insert $$Hello$$

Insert $$World$!$

Delete $$World$!$

Delete $$asdf$$

Undo

output$1.$txt

Hello World!

input$2.$txt

Undo

output$2.$txt

Insert $$Stacks are$$

Insert $$Fun$!$

Undo

Undo

input$3.$txt

Insert $$Lorem ipsum$$

Delete $$ipsum$$

Insert $$dolor sit$$

Undo

output$3.$txt

Lorem