The prefix form of A-B/ (C * D ^ E)?

Question

Could anyone please explain this answer?

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ever heard of polish notation? https://en.wikipedia.org/wiki/Polish_notation — mangusta, Oct 11 '19 at 17:27
@mangusta My sense is that the OP’s confusion is less about what the notation is and more about how the explanation makes sense given the answer. — templatetypedef, Oct 11 '19 at 17:36

score 1 · Answer 1 · answered Oct 11 '19 at 17:35

That explanation looks incorrect to me, even though the final answer looks correct. Let’s begin by taking the expression and fully parenthesizing it to show operator precedence:

A - (B / (C * (D^E)))

Notice that this doesn’t match the parenthesization given in the solution, which I suspect is an error in the answers. From here, we see that the top-level operator is the subtraction. The LHS is just the expression A, and the RHS is the expression B / (C * (D^E)), so we can do a partial conversion:

- A [[ whatever the expression is for B / (C * (D^E)) ]]

That nested expression has division as its top-level operator, so we can expand it like this:

- A / B [[ whatever the expression is for C * (D^E) ]]

Repeating this process gives us the following:

- A / B * C [[ whatever the expression is for D^E ]]
- A / B * C ^ D E

Hope this helps!

The prefix form of A-B/ (C * D ^ E)?

1 Answers1