postfix-notation

I'm studying for an exam on JavaScript at the moment. I've also got a little knowledge of C and Perl so I'm familiar with prefix and postfix notation in all three languages. I did an online practice exam for it and one mistake I made was in evaluating the following code: var x = 10; x += x--; Now, I thought it would evaluate to 19 because it would be 10 + 10, then subtract 1 to make 9. But the feedback I got was that it was wrong and it actually evaluates to 20. I thought that sounded a bit suspicious so I tested it out in an HTML document, and it came out with 20 again. I then tried the

I am looking for algorithm postfix to infix notation which will produce the minimum number of the parentheses. I have found that but it will produce many, many parentheses: http://tajendrasengar.blogspot.com/2011/09/postfix-to-infix-algorithm.html For example The input: <ONP>abcd*/+~ The result: <INF>~(a+b/(c*d)) What you need to do if you really want as few parentheses as possible, is similar to what the algorithm you linked to says. However... You should store an operator for each composite operand in the Stack . Namely, the last operator used in the operand. You could use a second Stack for

Here is a Python postfix notation interpreter which utilizes a stack to evaluate the expressions. Is it possible to make this function more efficient and accurate? #!/usr/bin/env python import operator import doctest class Stack: """A stack is a collection, meaning that it is a data structure that contains multiple elements. """ def __init__(self): """Initialize a new empty stack.""" self.items = [] def push(self, item): """Add a new item to the stack.""" self.items.append(item) def pop(self): """Remove and return an item from the stack. The item that is returned is always the last one that