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

What is class invariants assertion, What is Class invariants assertion ...

What is Class invariants assertion A class invariant is an assertion which should be true of any class instance before and after calls of its exported operations. Generally

Spanning trees, Spanning Trees: A spanning tree of a graph, G, refer to a ...

Spanning Trees: A spanning tree of a graph, G, refer to a set of |V|-1 edges which connect all vertices of the graph. There are different representations of a graph. They are f

Surrounding of sub division method, Surrounding of sub division method ...

Surrounding of sub division method A polygon surrounds a viewport if it completely encloses or covers the viewport. This happens if none of its sides cuts any edge of the viewp

Methods of collision resolution, Methods of Collision Resolution 1)  Co...

Methods of Collision Resolution 1)  Collision Resolution by separate chaining  2)  Collision Resolution by open addressing

Tree traversals, There are three kinds of tree traversals, namely, Postorde...

There are three kinds of tree traversals, namely, Postorder , Preorder and Inorder. Preorder traversal: Each of nodes is visited before its children are visited; first the roo

Double linked list, In a doubly linked list, also called as 2 way list, eac...

In a doubly linked list, also called as 2 way list, each node is divided into 3 parts. The first part is called previous pointer field. It contains the address of the preceding

Importance of object-oriented over java, Importance of Object-Oriented over...

Importance of Object-Oriented over java Java is basically based on OOP notions of classes and objects. Java uses a formal OOP type system that should be obeyed at compile-t

Perform depth -first search, You are given two jugs, a 4-gallon one and a 3...

You are given two jugs, a 4-gallon one and a 3-gallon one. Neither has any measuring marker on it. There is a tap that can be used to fill the jugs with water. How can you get exac

Pseudo code, I need help writing a pseudocode for my assignment can anyone ...

I need help writing a pseudocode for my assignment can anyone help?

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