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

Sorting, explain quick sort algorithm

explain quick sort algorithm

Structural Induction, Let a be a well-formed formula. Let c be the number o...

Let a be a well-formed formula. Let c be the number of binary logical operators in a. (Recall that ?, ?, ?, and ? are the binary logical operators). Let s be the number of proposit

Euclidean algorithm, The Euclidean algorithm is an algorithm to decide the ...

The Euclidean algorithm is an algorithm to decide the greatest common divisor of two positive integers. The greatest common divisor of N and M, in short GCD(M,N), is the largest in

Prims algorithm, how to write prims algorithms? with example

how to write prims algorithms? with example

Define data model, Define data model?  A data model is a collection of ...

Define data model?  A data model is a collection of conceptual tools for explaning data, data relationships, data semantics and consistency constraints.

The two famous methods for traversing, The two famous methods for traversin...

The two famous methods for traversing are:- a) Depth first traversal b) Breadth first

frequenty count of function, Ask question find frequency count of function...

Ask question find frequency count of function- {for(i=1;i {for(j=1;j {for(k=1;k } } }

Determine the importance of array, Determine the importance of array Ar...

Determine the importance of array Arrays are significant since they allow many values to be stored in a single data structure whereas providing very fast access to each value.

Memory allocation strategies, Q. Explain the various memory allocation stra...

Q. Explain the various memory allocation strategies.                                                            Ans. M e m ory Allocation Strategies are given as follow

Naïve recursive algorithm for binomial coefficients, How many recursive cal...

How many recursive calls are called by the naïve recursive algorithm for binomial coefficients, C(10, 5) and C(21, 12) C(n,k){c(n-1,k)+c(n-1,k-1) if 1 1 if k = n or k = 0

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