Postfix expression algorithm, Data Structure & Algorithms

Assignment Help:

Write an algorithm to calculate a postfix expression.  Execute your algorithm using the given postfix expression as your input : a b + c d +*f ↑ .

To evaluate a postfix expression by using the given values:

clear the stack

symb  = next input character while(not end of input)

{

if (symb is an operand)

push onto the stack;

else

{

pop two operands from the stack;

result=op1 symb op2;

push result onto the stack;

}

symb = next input character;

}

return (pop (stack));

The input postfix expression is given as:- ab+cd+*f^

Symb                 Stack                                          Evaluation a    a

b                    a b

+                   pop a and b                                 (a + b) Push (a + b)

c                    (a + b) c

d                   (a + b) c d

+                   pop c and d                                 (c + d) Push (c + d)

*                    pop (a + b) and (c + d)                (a + b) * (c + d)

f                    (a + b) * (c + d) f

^                    pop (a + b) * (c + d) and f           (a + b) * (c + d) ^ f

The result of evaluation is ((a + b) * (c + d)) ^ f


Related Discussions:- Postfix expression algorithm

Direct file organisation, It offers an effective way to organize data while...

It offers an effective way to organize data while there is a requirement to access individual records directly. To access a record directly (or random access) a relationship is

Algorithm, Example of worse case of time

Example of worse case of time

Define binary tree, Define Binary Tree  A binary tree T is explained as...

Define Binary Tree  A binary tree T is explained as a finite set of nodes that is either empty or having of root and two disjoint binary trees TL, and TR known as, respectively

Travelling salesman problem, Example 3: Travelling Salesman problem G...

Example 3: Travelling Salesman problem Given: n associated cities and distances among them Find: tour of minimum length that visits all of city. Solutions: How several

2 way merge sort, merge sort process for an example array {38, 27, 43, 3, 9...

merge sort process for an example array {38, 27, 43, 3, 9, 82, 10}. If we take a closer look at the diagram, we can see that the array is recursively divided in two halves till the

Explain space complexity, Explain Space Complexity Space Complexity :...

Explain Space Complexity Space Complexity :- The space complexity of an algorithm is the amount of memory it requires to run to completion. Some of the reasons to study space

Linear search, Linear search is not the most efficient way to search an ite...

Linear search is not the most efficient way to search an item within a collection of items. Though, it is extremely simple to implement. Furthermore, if the array elements are arra

Binary trees, A binary tree is a special tree where each non-leaf node can ...

A binary tree is a special tree where each non-leaf node can have atmost two child nodes. Most important types of trees which are used to model yes/no, on/off, higher/lower, i.e.,

Row major representation, Row Major Representation In memory the primar...

Row Major Representation In memory the primary method of representing two-dimensional array is the row major representation. Under this representation, the primary row of the a

Define big omega notation, Define Big Omega notation Big Omega notatio...

Define Big Omega notation Big Omega notation (?) : The lower bound for the function 'f' is given by the big omega notation (?). Considering 'g' to be a function from the non-n

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd