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

Splaying procedure, For splaying, three trees are maintained, the central, ...

For splaying, three trees are maintained, the central, left & right sub trees. At first, the central subtree is the complete tree and left and right subtrees are empty. The target

Define null values, Define null values.  In some cases a particular ent...

Define null values.  In some cases a particular entity might not have an applicable value for an attribute or if we do not know the value of an attribute for a particular entit

Rooted tree, It does not have any cycles (circuits, or closed paths), which...

It does not have any cycles (circuits, or closed paths), which would imply the existence of more than one path among two nodes. It is the most general kind of tree, and might be co

Acyclic graph, Tree is a widely used data structure employed for representi...

Tree is a widely used data structure employed for representing several problems. We studied tree like a special case of acyclic graph. Though, rooted trees are most prominent of al

Algorithm for determining strongly connected components, Algorithm for dete...

Algorithm for determining strongly connected components of a Graph: Strongly Connected Components (G) where d[u] = discovery time of the vertex u throughout DFS , f[u] = f

Linked list implementation of a dequeue, Double ended queues are implemente...

Double ended queues are implemented along doubly linked lists. A doubly link list can traverse in both of the directions as it contain two pointers namely left pointers and righ

Data Structure, Ask consider the file name cars.text each line in the file ...

Ask consider the file name cars.text each line in the file contains information about a car ( year,company,manufacture,model name,type) 1-read the file 2-add each car which is repr

Implementation of circular queues, One of the main problems with the linear...

One of the main problems with the linear queue is the lack of appropriate utilization of space. Assume that the queue can store 100 elements & the complete queue is full. Thus, it

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