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

Inorder traversal, Inorder traversal: The left sub tree is visited, then t...

Inorder traversal: The left sub tree is visited, then the node and then right sub-tree. Algorithm for inorder traversal is following: traverse left sub-tree visit node

Graphs, floyd warshall algorithm

floyd warshall algorithm

Write about enterprise manager, Question 1 . Give the structure of PL/SQL B...

Question 1 . Give the structure of PL/SQL Blocks and explain Question 2 . Differentiate between PL/SQL functions and procedures Question 3 . Explain the following Par

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,

Threaded binary tree, i need the full concept of it... please can anyone pr...

i need the full concept of it... please can anyone provide

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.

Undirected graph and adjacency matrix, Q. Consider the specification writte...

Q. Consider the specification written below of a graph G V(G ) = {1,2,3,4} E(G ) = {(1,2), (1,3), (3,3), (3,4), (4,1)} (i)        Draw the undirected graph. (

Splay trees, Addition of new records in a Binary tree structure always occu...

Addition of new records in a Binary tree structure always occurs as leaf nodes, which are further away from the root node making their access slower. If this new record is to be ac

Algorithm, implement multiple stacks in a single dimensional array. write a...

implement multiple stacks in a single dimensional array. write algorithm for various stack operation for them

Red-black tree after insertion, The above 3 cases are also considered conve...

The above 3 cases are also considered conversely while the parent of Z is to the right of its own parent. All the different kind of cases can be illustrated through an instance. Le

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