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

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?

Tree Traversal, If preorder traversal and post order traversal is given the...

If preorder traversal and post order traversal is given then how to calculate the pre order traversal. Please illustrate step by step process

Multiple stack, implement multiple stack in single dimensionl array.write a...

implement multiple stack in single dimensionl array.write algorithms for various stack operation for them

Link list, algorithm for multiplication of two sparse matrices using link l...

algorithm for multiplication of two sparse matrices using link list

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.

Give the example of bubble sort algorithm, Give the example of bubble sort ...

Give the example of bubble sort algorithm For example List: - 7 4 5 3 1. 7 and 4 are compared 2. Since 4 3. The content of 7 is now stored in the variable which was h

State z-buffer algorithm, Z-Buffer Algorithm Also known as the Depth-Bu...

Z-Buffer Algorithm Also known as the Depth-Buffer algorithm, this image-space method simply selects for  display the polygon or portion of a polygon that is nearest to the view

Perfect matching polytope ppm, Let G=(V,E) be a graph for which all nodes h...

Let G=(V,E) be a graph for which all nodes have degree 5 and where G is 5-edge is connected. a) Show that the vector x which is indexed by the edges E and for which xe = 1/5 for

State phong shading, Phong Shading Phong shading too is based on interp...

Phong Shading Phong shading too is based on interpolation, but instead of interpolating the colour value, it is the normal vector, which is interpolated for each point and a co

Algorithm for linear search, Here,  m represents the unordered array of ele...

Here,  m represents the unordered array of elements n  represents number of elements in the array and el  represents the value to be searched in the list Sep 1: [Initialize]

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