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 an avl tree, For AVL trees the deletion algorithm i...

For AVL trees the deletion algorithm is a little more complicated as there are various extra steps involved in the deletion of node. If the node is not a leaf node, then it contain

Calculate the k-th power and recursive algorithem, 1. The following is a r...

1. The following is a recursive algorithm to calculate the k -th power of 2. Input k a natural number Output kth power of 2 Algorithem: If k =0then return 1 Else return 2* po

Operating system, discuss the operating system under the following: MONOLIT...

discuss the operating system under the following: MONOLITHIC SYSTEM,LAYER SYSTEM AND VIRTUAL MACHINES

What are the objectives of visual realism applications, What are the Object...

What are the Objectives of visual realism applications After studying this unit, you should be able to know specific needs of realism, add realism to pictures by el

Depth first traversal, A depth-first traversal of a tree visits a nodefirst...

A depth-first traversal of a tree visits a nodefirst and then recursively visits the subtrees of that node. Similarly, depth-first traversal of a graph visits a vertex and then rec

Difference between array and abstract data types, Difference between array ...

Difference between array and abstract data types Arrays aren't abstract data types since their arrangement in the physical memory of a computer is an essential feature of their

Implementation of a binary tree, Like general tree, binary trees are implem...

Like general tree, binary trees are implemented through linked lists. A typical node in a Binary tree has a structure as follows struct NODE { struct NODE *leftchild; i

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

Data structures, 1.  You are required to hand in both a hard copy and an el...

1.  You are required to hand in both a hard copy and an electronic copy of the written report on the project described in A, including all the diagrams you have drawn.  2.  You

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