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 smallest element of an array''s index, The smallest element of an array...

The smallest element of an array's index is called its Lower bound.

Design a doubly linked list, Instructions : You have to design a dou...

Instructions : You have to design a doubly linked list container. The necessary classes and their declarations are given below The main() function for testing the yo

How does an array differ from an ordinary variable, Normal 0 fa...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Time complexity, The  total  of  time  needed  by  an algorithm to run to i...

The  total  of  time  needed  by  an algorithm to run to its completion is termed as time complexity. The asymptotic running time of an algorithm is given in terms of functions. Th

Flow chart, What is tha flow chart of algorithm

What is tha flow chart of algorithm

Explain the question, Merging 4 sorted files having 50, 10, 25 and 15 recor...

Merging 4 sorted files having 50, 10, 25 and 15 records will take time

Heap sort, We will start by defining a new structure called Heap. Figure 3 ...

We will start by defining a new structure called Heap. Figure 3 illustrates a Binary tree. Figure: A Binary Tree A complete binary tree is said to assure the 'heap con

Order of linear search, a. In worst case the order of linear search is O (n...

a. In worst case the order of linear search is O (n/2) b. Linear search is more competent than Binary search. c. For Binary search, the array must be sorted in ascending orde

Maximum degree of any vertex in a simple graph, The maximum degree of any v...

The maximum degree of any vertex in a simple graph with n vertices is (n-1) is the maximum degree of the vertex in a simple graph.

Program to implementing stack using linked lists, include include i...

include include include /* Definition of structure node */ typedef struct node { int data; struct node *next; } ; /* Definition of push function */

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