Postfix expression algorithm, Data Structure & Algorithms

Assignment Help:

Write an algorithm to calculate a postfix expression.  Execute your algorithm using the given postfix expression as your input : a b + c d +*f ↑ .

To evaluate a postfix expression by using the given values:

clear the stack

symb  = next input character while(not end of input)

{

if (symb is an operand)

push onto the stack;

else

{

pop two operands from the stack;

result=op1 symb op2;

push result onto the stack;

}

symb = next input character;

}

return (pop (stack));

The input postfix expression is given as:- ab+cd+*f^

Symb                 Stack                                          Evaluation a    a

b                    a b

+                   pop a and b                                 (a + b) Push (a + b)

c                    (a + b) c

d                   (a + b) c d

+                   pop c and d                                 (c + d) Push (c + d)

*                    pop (a + b) and (c + d)                (a + b) * (c + d)

f                    (a + b) * (c + d) f

^                    pop (a + b) * (c + d) and f           (a + b) * (c + d) ^ f

The result of evaluation is ((a + b) * (c + d)) ^ f


Related Discussions:- Postfix expression algorithm

Acyclic graphs, Acyclic Graphs In a directed graph a path is said to fo...

Acyclic Graphs In a directed graph a path is said to form a cycle is there exists a path (A,B,C,.....P) such that A = P. A graph is called acyclic graph if there is no cycle in

Deletion of a node from a binary search tree, The algorithm to delete any n...

The algorithm to delete any node having key from a binary search tree is not simple where as several cases has to be considered. If the node to be deleted contains no sons,

Explain the term - branching, Explain the term - Branching There are t...

Explain the term - Branching There are two common ways of branching: case of ..... otherwise ...... endcase  if ..... then ..... else ..... endif   case of

Multiple stacks, how multiple stacks can be implemented using one dimension...

how multiple stacks can be implemented using one dimensional array

For loop, for (i = 0; i sequence of statements } Here, the loop e...

for (i = 0; i sequence of statements } Here, the loop executes n times. Thus, the sequence of statements also executes n times. Since we suppose the time complexity of th

Make adjacency matrix for un-directed graph, Q. Describe the adjacency matr...

Q. Describe the adjacency matrix and make the same for the given undirected graph.    Ans: The representation of Adjacency Matrix: This representation consists of

Accept a file and form a binary tree - huffman encoding, Huffman Encoding i...

Huffman Encoding is one of the very simple algorithms to compress data. Even though it is very old and simple , it is still widely used (eg : in few stages of JPEG, MPEG etc). In t

Terminology used for files structures, Given are the definitions of some im...

Given are the definitions of some important terms: 1) Field: This is an elementary data item characterized by its size, length and type. For instance, Name

Data structure for representing numbers, Your first task will be to come up...

Your first task will be to come up with an appropriate data structure for representing numbers of arbitrary potential length in base 215. You will have to deal with large negative

Search on a heap file, Consider the file " search_2013 ". This is a text fi...

Consider the file " search_2013 ". This is a text file containingsearch key values; each entry is a particular ID (in the schema given above). You are tosimulate searching over a h

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