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

Optimization Methods, Optimal solution to the problem given below. Obtain t...

Optimal solution to the problem given below. Obtain the initial solution by VAM Ware houses Stores Availibility I II III IV A 5 1 3 3 34 B 3 3 5 4 15 C 6 4 4 3 12 D 4 –1 4 2 19 Re

Stacks, reverse the order of elements on a stack S using two additional sta...

reverse the order of elements on a stack S using two additional stacks using one additional stack

Explain about the containers, Containers Introduction Simple abstr...

Containers Introduction Simple abstract data types are useful for manipulating simple sets of values, such as integers or real numbers however more complex abstract data t

Calculus, basic calculation for algorith.

basic calculation for algorith.

Define a b-tree, Define a B-Tree Justas AVL trees are balanced binary s...

Define a B-Tree Justas AVL trees are balanced binary search trees, B-trees are balanced M-way search trees. A B-Tree of order M is either the empty tree or it is an M-way searc

Abstract Data Types, A useful tool which is used for specifying the logical...

A useful tool which is used for specifying the logical properties of a data type is called the abstract data type or ADT. The term "abstract data type" refers to the fundamental ma

Data structure- tree, Tree is dynamic data structures. Trees can expand & c...

Tree is dynamic data structures. Trees can expand & contract as the program executes and are implemented via pointers. A tree deallocates memory whereas an element is deleted.

Breadth-first search, Breadth-first search starts at a given vertex h, whic...

Breadth-first search starts at a given vertex h, which is at level 0. In the first stage, we go to all the vertices that are at the distance of one edge away. When we go there, we

State cmy model, CMY Model  The cyan, magenta, yellow (CMY) colour mode...

CMY Model  The cyan, magenta, yellow (CMY) colour model is a subtractive model based on the colour absorption properties of paints and inks. As such it has become the standard

Define midsquare method, Midsquare Method :- this operates in 2 steps. In t...

Midsquare Method :- this operates in 2 steps. In the first step the square of the key value K is taken. In the 2nd step, the hash value is obtained by deleting digits from ends of

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