At start, the user has to click the Load button. The load button will open a file chooser to select an

equation file. The selected file will be displayed in the label next to the load button $($e$.$g$.$ c:$\backslash$data$\backslash$DS$-$

Proj$2\mathrm{.}242)$ and then the file contents will be loaded as shown in previous figure if the file is

valid$($e$.$g$.$ tags are balanced$).$

Valid file: you need to check and indicate whether the file tags are balanced or not. Meaning that

each start tag has an end tag and they are closed in order.

Note: This can be done using a stack similar to the balanced delimiters in equations.

In the Equation Section you need to load equations from the $1^{st}$ section from the file.

For Infix equations: do convert the infix to postfix and then evaluate it$.$

For postfix equations: do convert the postfix to prefix and then evaluate it$.$ As shown in the

previous figure.

Note: we didn't cover prefix in lectures. You need to study it by yourself.

At last, the Prev and Next buttons will navigate through equation section. If you click the Next button,

it will display the equations from the $2^{nd}$ section in the file if exists and so on$.$ If you click the Prev

button, it will display the equations from the previous section in the file if exists.

To make the project more interesting:

We need you to implement the linked stack using a

cursor array.

You have to define $1$ course array and within this cursor

array you can create as many stacks as needed.

Yahoooo!