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

Array implementation of lists, In the array implementation of the lists, we...

In the array implementation of the lists, we will use the array to hold the entries and a separate counter to keep track of the number of positions are occupied. A structure will b

Enumerate the types in ruby, Enumerate the Types in Ruby Ruby is a pure...

Enumerate the Types in Ruby Ruby is a pure object-oriented language, meaning that all types in Ruby are classes, and each value in a Ruby program is an instance of a class. Thi

Aa-trees, Red-Black trees have introduced a new property in the binary sear...

Red-Black trees have introduced a new property in the binary search tree that means an extra property of color (red, black). However, as these trees grow, in their operations such

Doubly linked lists-implementation, In any singly linked list, each of the ...

In any singly linked list, each of the elements contains a pointer to the next element. We have illustrated this before. In single linked list, traversing is probable only in one d

Hashing and hash functions, Q. Describe the term hashing. Explain any two u...

Q. Describe the term hashing. Explain any two usually used hash functions. Explain one method of collision resolution.

List various problem solving techniques, List various problem solving techn...

List various problem solving techniques. There are two techniques:- 1.  Top down 2.  Bottom- up

Consistent heuristic function - graph search, Consistent Heuristic Function...

Consistent Heuristic Function - Graph Search Recall the notions of consistency and admissibility for an A* search heuristic. a. Consider a graph with four nodes S, A, B, C,

Algorithm for dfs, Step 1: Choose a vertex in the graph and make it the sou...

Step 1: Choose a vertex in the graph and make it the source vertex & mark it visited. Step 2: Determine a vertex which is adjacent to the source vertex and begun a new search if

How can a lock object be called in the transaction, How can a lock object b...

How can a lock object be called in the transaction? By calling Enqueue and Dequeue in the transaction.

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