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

File organization, Define File organization''s and it''s types

Define File organization''s and it''s types

Insertion of a key into a b-tree, Example: Insertion of a key 33 into a B-...

Example: Insertion of a key 33 into a B-Tree (w/split) Step 1: Search first node for key closet to 33. Key 30 was determined. Step 2: Node pointed through key 30, is se

Dgsd, Ask question #sdgsdgsdginimum 100 words accepted#

Ask question #sdgsdgsdginimum 100 words accepted#

Find longest repeat prefix of string - linear time algorithm, 1. A string s...

1. A string s is said to be periodic with a period α, if s is α k for some k > 2. (Note that α k is the string formed by concatenating k times.) A DNA sequence s is called a tand

Algorithm, write an algorithm given each students name and grade points for...

write an algorithm given each students name and grade points for six courses.find his grade point average and group students into the gpa groups 3.5

Addressing modes, Compare zero-address, one-address, two-address, and three...

Compare zero-address, one-address, two-address, and three-address machines by writing programs to compute: Y = (A – B X C) / (D + E X F) for each of the four machines. The inst

Depth of complete binary tree, What will be depth do , of complete binary t...

What will be depth do , of complete binary tree of n nodes, where nodes are labelled from 1 to n with root as node and last leaf node as node n

Process of channel access, Channel access In first generation systems, ...

Channel access In first generation systems, every cell supports a number of channels. At any given time a channel is allocated to only one user. Second generation systems also

What is efficiency of algorithm, What is Efficiency of algorithm? Effic...

What is Efficiency of algorithm? Efficiency of an algorithm can be precisely explained and investigated with mathematical rigor.  There are two types of algorithm efficiency

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