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

The time and space complexities of an algorihm, Relation between the time a...

Relation between the time and space complexities of an algorithm The examining of algorithm focuses on time complexity and space complexity. As compared to time analysis, the a

Illustrate the wire frame representation, RENDERING, SHADING AND COLOURING ...

RENDERING, SHADING AND COLOURING By introducing hidden line removal we have already taken one step away from wire-frame drawings towards being able to realistically model and d

Explain np-complete decision problem, a. Determine the result of inserting ...

a. Determine the result of inserting the keys 4,19, 17, 11, 3, 12, 8, 20, 22, 23, 13, 18, 14, 16, 1, 2, 24, 25, 26, 5 in order to an empty B-Tree of degree 3. Only draw the configu

Sorting, Retrieval of information is made simpler when it is stored into so...

Retrieval of information is made simpler when it is stored into some predefined order. Therefore, Sorting is a very important computer application activity. Several sorting algorit

Define big oh notation, Big oh notation (O) : The upper bound for the funct...

Big oh notation (O) : The upper bound for the function 'f' is given by the big oh notation (O). Considering 'g' to be a function from the non-negative integers to the positive real

Applications, Arrays are simple, however reliable to employ in more conditi...

Arrays are simple, however reliable to employ in more condition than you can count. Arrays are utilized in those problems while the number of items to be solved out is fixed. They

Programs, Develop a program that accepts the car registration( hint: LEA 43...

Develop a program that accepts the car registration( hint: LEA 43242010)

Interest rate, explain the determination of interest rate in the classical ...

explain the determination of interest rate in the classical system.

Which sorting algorithms not have running time of o (n2), Which sorting al...

Which sorting algorithms does not have a worst case running time of  O (n 2 ) ? Merge sort

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