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

Stack, how we will make projects on stack in c?

how we will make projects on stack in c?

Binary search technique, Q. Describe the basic concept of binary search tec...

Q. Describe the basic concept of binary search technique? Is it more efficient than the sequential search?         Ans : The bin ary search technique:- This tec

Implement an open hash table, In a chained hash table, each table entry is ...

In a chained hash table, each table entry is a pointer to a collection of elements. It can be any collection that supports insert, remove, and find, but is commonly a linked list.

Deletion of any element from the queue, Program segment for the deletion of...

Program segment for the deletion of any element from the queue delmq(i)  /* Delete any element from queue i */ { int i,x; if ( front[i] == rear[i]) printf("Queue is

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

Complexity of quick sort, Q. What do you mean by the best case complexity o...

Q. What do you mean by the best case complexity of quick sort and outline why it is so. How would its worst case behaviour arise?

A binary tree of depth "d" is an almost complete binary tree, A binary tree...

A binary tree of depth "d" is an almost complete binary tree if  A) Every leaf in the tree is either at level "d" or at level "d-1"  B)  For any node "n" in the tree with a

Hashing and hash functions, Q. Describe the term hashing. Explain any two u...

Q. Describe the term hashing. Explain any two usually used hash functions. Explain one method of collision resolution.

Implementation of queue, For a queue a physical analogy is a line at bookin...

For a queue a physical analogy is a line at booking counter. At booking counter, customers go to the rear (end) of the line & customers are attended to several services from the fr

Balance theorem, Question 1 Discuss the following theorems with respect to...

Question 1 Discuss the following theorems with respect to Splay Trees- Balance Theorem Dynamic Finger Theorem   Question 2 Write a C program for implementation

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