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

Encryption the plain-text using the round keys, Encryption the plain-text u...

Encryption the plain-text using the round keys: 1. (Key schedule) Implement an algorithm that will take a 128 bit key and generate the round keys for the AES encryption/decryp

Explain the memory function method, Explain the Memory Function method ...

Explain the Memory Function method The Memory Function method seeks to combine strengths of the top  down and bottom-up approaches  to  solving  problems  with  overlapping  su

State a algorithm that inputs the heights of all 500 student, As part of an...

As part of an experiment, a school measured heights (in metres) of all its 500 students. Write an algorithm, using a flowchart that inputs the heights of all 500 students and ou

Define tree ?, A tree is a non-empty set one component of which is designat...

A tree is a non-empty set one component of which is designated the root of the tree while the remaining components are partitioned into non-empty groups each of which is a subtree

Sparse metrics, Q. Define the sparse metrics and also explain the represent...

Q. Define the sparse metrics and also explain the representation of a 4X4 matrix using linked list.         Ans: A matrix in which number of zero entries is quite h

Queue, what''s queue ?

what''s queue ?

Explain the term group support system, (a) Explain the term Group Support S...

(a) Explain the term Group Support System and elaborate on how it can improve groupwork. (b) Briefly explain three advantages of simulation. (c) Explain with the help of a

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

Program segment for deletion of any element from the queue delete() { int delvalue = 0; if (front == NULL) printf("Queue Empty"); { delvalue = front->value;

The number of different directed trees with 3 nodes, The number of differen...

The number of different directed trees with 3 nodes are ?? The number of disimilar directed trees with three nodes are 3

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