Algorithm to evaluate expression given in postfix notation , Data Structure & Algorithms

Assignment Help:

Q. Write down an algorithm to evaluate an expression given to you in postfix notation. Show the execution of your algorithm for the following given expression.

AB^CD-EF/GH+/+*                                                                               

Ans.

Algorithm to evaluate Post fix Expression is shown as follows

 

Opndstk = the empty stack;

/*scan the input string reading one */

/*element at a time into symb */

while ( not end of input){

symb  = next input character;

if (symb is an operand)

push (opndstk, symb);

else

{

/* symb is an operator */

opnd 2 = Pop (opnd stk);

opnd 1 = Pop (opnd stk);

value = result of applying symb to opnd 1 and opnd 2;

push (opndstk,value);

}/*end else */

}/*end while */

return (pop (opnd stk));

AB^CD-EF/GH+/+*

Symb

Opnd1

Opnd2

Value

Opndstk

A

 

 

 

A

B

 

 

 

A,B

^

A

B

A^B

A^B

C

A

B

A^B

A^B,C

D

A

B

A^B

A^B,C,D

-

C

D

C-D

A^B,C-D

E

C

D

C-D

A^B,C-D,E

F

C

D

C-D

A^B,C-D,E,F

/

E

F

E/F

A^B,C-D,E/F

G

E

F

E/F

A^B,C-D,E/F,G

H

E

F

E/F

A^B,C-D,E/F,G,H

+

G

H

G+H

A^B,C-D,E/F,G+H

/

E/F

G+H

(E/F)/(G+H)

A^B,C-D, (E/F) /(G+H)

+

C-D

(E/F)/(G+H)

(C-D)+(E/F)/(G+H)

A^B,(C-D)+

(E/F)/(G+H)

*

A^B

(C-

D)+(E/F)/(G+H)

A^B*((C-D)+

(E/F)/(G+H))

A^B*((C-D)+

(E/F)/(G+H))


Related Discussions:- Algorithm to evaluate expression given in postfix notation

Write an algorithm inputs speed of cars using pseudocode, Write an algorith...

Write an algorithm by using pseudocode which: Inputs top speeds of 5000 cars Outputs fastest speed and the slowest speed Outputs average speed of all the 5000 cars

Just a quick couple questions, I was wanting to know where this web site wa...

I was wanting to know where this web site was created. My second question is,,, are the online tuters accredited teachers? If they are, are they only working for the website or ma

Multilist file organisation, what is multilist length file organisation? ex...

what is multilist length file organisation? explain with an example

How do collisions happen during hashing, How do collisions happen during ha...

How do collisions happen during hashing? Usually the key space is much larger than the address space, thus, many keys are mapped to the same address. Assume that two keys K1 an

Explain the representations of graph, Explain the representations of graph....

Explain the representations of graph. The different ways of representing a graph is: Adjacency list representation : This representation of graph having of an array Adj of

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

Explain the term totalling, Explain the term totalling To add up a ser...

Explain the term totalling To add up a series numbers the subsequent type of statement must be used: Total = total + number  This literally means (new) total = (old) t

Pest control program, PART- Pest Control Program Prepare a Pest Contro...

PART- Pest Control Program Prepare a Pest Control Program for the facility that will address the management of Rodents, Insects and Birds. Your Pest Control Program should

Define heap, HEAP  A heap is described to be a binary tree with a key i...

HEAP  A heap is described to be a binary tree with a key in every node, such that  1-All the leaves of the tree are on 2 adjacent levels. 2- All leaves on the lowest leve

Question, A binary search tree is used to locate the number 43. Which of th...

A binary search tree is used to locate the number 43. Which of the following probe sequences are possible and which are not? Explain. (a) 61 52 14 17 40 43 (b) 2 3 50 40 60 43 (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