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

Graph connectivity, A connected graph is a graph wherein path exists among ...

A connected graph is a graph wherein path exists among every pair of vertices. A strongly connected graph is a directed graph wherein every pair of distinct vertices is connecte

Methods of physically storing data in the files, This unit dealt along with...

This unit dealt along with the methods of physically storing data in the files. The terms fields, records & files were described. The organization types were introduced. The sev

Explain backtracking, Explain Backtracking The  principal idea is to co...

Explain Backtracking The  principal idea is to construct solutions single component  at a time  and evaluate such  partially constructed candidates as follows. If a partiall

Explain depth-first traversal, Depth-first traversal A depth-first t...

Depth-first traversal A depth-first traversal of a tree visit a node and then recursively visits the subtrees of that node. Likewise, depth-first traversal of a graph visits

Functions for inserting and deleting at either end of deque, Q. Devise a re...

Q. Devise a representation for a given list where insertions and deletions can be made at both the ends. Such a structure is called Deque (which means Double ended queue). Write fu

Determine the area subdivision method, Area Subdivision Method In this ...

Area Subdivision Method In this method, the viewport is examined for clear decisions on the polygons situated in it, in regard to their overlap and visibility to the viewer. Fo

Lists, In the earlier unit, we have discussed about the arrays. Arrays are ...

In the earlier unit, we have discussed about the arrays. Arrays are data structures of fixed size. Insertion & deletion involves reshuffling of array elements. Thus, arraymanipulat

Method for keeping two stacks within a single linear array, Q. Define a met...

Q. Define a method for keeping two stacks within a single linear array S in such a way that neither stack overflows until entire array is used and a whole stack is never shifted to

Multiple queue, #questionalgorithm for implementing multiple\e queues in a ...

#questionalgorithm for implementing multiple\e queues in a single dimensional array

Infix notation to postfix notation, Which data structure is required to cha...

Which data structure is required to change infix notation to postfix notation?    Stack function is used to change infix notation to postfix notatio 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