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

Deletion of a node from a binary search tree, The algorithm to delete any n...

The algorithm to delete any node having key from a binary search tree is not simple where as several cases has to be considered. If the node to be deleted contains no sons,

Explain floyds algorithm, Explain Floyd's algorithm It is convenient to...

Explain Floyd's algorithm It is convenient to record the lengths of shortest paths in an n by n matrix D known as the  distance matrix: the element d ij   in the i th   row an

Algorithm that counts number of nodes in a linked list, Q. Write an algorit...

Q. Write an algorithm that counts number of nodes in a linked list.                                       A n s . Algo rithm to Count No. of Nodes in Linked List C

Data communication, #question.explain different types of errors in data tra...

#question.explain different types of errors in data transmission.

Pseudo code, I need help writing a pseudocode for my assignment can anyone ...

I need help writing a pseudocode for my assignment can anyone help?

Red black tree, red black tree construction for 4,5,6,7,8,9

red black tree construction for 4,5,6,7,8,9

Graph, For the following graph find the adjacency matrix and adjacency list...

For the following graph find the adjacency matrix and adjacency list representation of the graph.

A full binary tree with n leaves, A full binary tree with n leaves have:- ...

A full binary tree with n leaves have:- 2n -1 nodes.

Non-recursive implementation of preorder traversal, For preorder traversal,...

For preorder traversal, in the worst case, the stack will rise to size n/2, where n refer to number of nodes in the tree. Another method of traversing binary tree non-recursively t

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