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

Sort 5, The number of interchanges needed to sort 5, 1, 6, 2 4 in ascending...

The number of interchanges needed to sort 5, 1, 6, 2 4 in ascending order using Bubble Sort is 5

Polynomials - represented by using arrays, /* the program accepts two polyn...

/* the program accepts two polynomials as a input & prints the resultant polynomial because of the addition of input polynomials*/ #include void main() { int poly1[6][

Splaying steps - splay trees, Readjusting for tree modification calls for r...

Readjusting for tree modification calls for rotations in the binary search tree. Single rotations are possible in the left or right direction for moving a node to the root position

Algorithms, characteristics of a good algorithm

characteristics of a good algorithm

Algorithm, Define what an algorithm is and outline the characteristics of a...

Define what an algorithm is and outline the characteristics of a good algorithm.

Example of telephone directory, A telephone directory having n = 10 records...

A telephone directory having n = 10 records and Name field as key. Let us assume that the names are stored in array 'm' i.e. m(0) to m(9) and the search has to be made for name "X"

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

Explain in brief about the container, Explain in brief about the Container ...

Explain in brief about the Container An entity which holds finitely many other entities. Just as containers such as boxes, baskets, bags, pails, cans, drawers, and so for

Avl trees, An AVL tree is a binary search tree that has the given propertie...

An AVL tree is a binary search tree that has the given properties: The sub-tree of each of the node differs in height through at most one. Each sub tree will be an AVL tre

Graph & optimal scheduling, You are given an undirected graph G = (V, E) in...

You are given an undirected graph G = (V, E) in which the edge weights are highly restricted. In particular, each edge has a positive integer weight of either {1,2,...,W}, where W

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