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

Graph, multilist representation of graph

multilist representation of graph

What is assertions and abstract data types, Assertions and Abstract Data Ty...

Assertions and Abstract Data Types Even though we have defined assertions in terms of programs, notion can be extended to abstract data types (which are mathematical entities).

Explain graph traversal, Graph Traversal In many problems we wish to in...

Graph Traversal In many problems we wish to investigate all the vertices in a graph in some systematic order. In graph we often do not have any single vertex singled out as spe

State about the pre- and post conditions, State about the pre- and post con...

State about the pre- and post conditions Programmers can easily document other pre- and post conditions and class invariants, though, and insert code to check most value preco

Full binary trees, Full Binary Trees: A binary tree of height h that had 2...

Full Binary Trees: A binary tree of height h that had 2h -1 elements is called a Full Binary Tree. Complete Binary Trees: A binary tree whereby if the height is d, and all of

Name the four data type groups, There are four data type groups:  I...

There are four data type groups:  Integer kepts whole numbers and signed numbers Floating-point Stores real numbers (fractional values). Perfect for storing bank deposit

Technique for direct search, Technique for direct search is    Hashing ...

Technique for direct search is    Hashing is the used for direct search.

Program to implementing stack using linked lists, include include i...

include include include /* Definition of structure node */ typedef struct node { int data; struct node *next; } ; /* Definition of push function */

Darw a flowchart for inputs number of hours of sunshine, This algorithm inp...

This algorithm inputs number of hours of sunshine recorded every day for a week (7 days). Output is the highest value for hours of sunshine and average (mean) value for numbers of

STACK, WHAT IS THE PURPOSE OF STACK IN C

WHAT IS THE PURPOSE OF STACK IN C

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