Thread: Anybody understand Postfix expressions

Originally Posted by DrunkieTheBear

Cause they are actually kicking my ass....

Here's the expression:
70 14 4 5 15 3 / * - - / 6 + =

I came up with -18

Work:
(70 / 14) - 4 - 5 * (15 / 3) + 6
(5) - 4 - 5 * (5) + 6
1 - 25 + 6
-24 + 6
-18

Anybody got any input?

You guys are funny. For the original question, not sure if the others were just BSing cause they didn't show their work like you. I havn't done postfix expressions or reverse Polish ( I guess Polish are backwards LOL), but I'm really good with math, Algebra and the sorts. I havn't done programming since I was in school, but if you post a similar length problem from a text book with the answer. I'm pretty sure I can figure this one out. Googling, I only found problems with about 4 numbers. If I figure it out before you post something from a book, I'll post again. Your work looks good using PEMDAS, but I don't know how to translate to the first line of your work.

Originally Posted by SlowNA06

Super-honest, the calculator is never wrong. Always check your work with a calculator.

Ah, didn't know you guys were using calculators. We weren't allowed. I always had to write it out to show how I got the answer even if I did it in my head.

Non-scientific calculators don't take in to consideration the order of operations.

anyways, I got my homework back and I had it right along with all the other postfix expressions on the homework.

Who wants to do my Stacks and Queues Coding?