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

Explain thread, Thread By changing the NULL lines in a binary tree to ...

Thread By changing the NULL lines in a binary tree to special links known as threads, it is possible to perform traversal, insertion and deletion without using either a stack

Determine the warnock algorithm, Warnock's Algorithm A divide and conqu...

Warnock's Algorithm A divide and conquer algorithm Warnock (PolyList PL, ViewPort VP) If (PL simple in VP) then Draw PL in VP, else Split VP vertically and horiz

Stacks, Q. Explain w hat are the stacks? How can we use the stacks  to chec...

Q. Explain w hat are the stacks? How can we use the stacks  to check whether an expression is correctly parentheses or not. For example (()) is well formed but (() or )()( is not w

How to write binary search algorithm?, Q. Write down the binary search algo...

Q. Write down the binary search algorithm and trace to search element 91 in following given list: 13          30          62           73         81         88             91

Last in first out method, This method is the reverse of FIFO and assumes th...

This method is the reverse of FIFO and assumes that each issue of stock is made from latest items received in the enterprises .Thus if the last lot to be received is not sufficient

Psedocodes, write a pseudocode to input the top speed (in km''s/hours) of 5...

write a pseudocode to input the top speed (in km''s/hours) of 5000 cars output the fastest speed and the slowest speed output the average (mean) speed of all the 5000 cars answers

Data structures, 1.  You are required to hand in both a hard copy and an el...

1.  You are required to hand in both a hard copy and an electronic copy of the written report on the project described in A, including all the diagrams you have drawn.  2.  You

Define tractable and intractable problems, Define tractable and intractable...

Define tractable and intractable problems Problems that can be solved in polynomial time are known as tractable problems, problems that cannot be solved in polynomial time are

Implementation of dequeue, Dequeue (a double ended queue) is an abstract da...

Dequeue (a double ended queue) is an abstract data type alike to queue, where insertion and deletion of elements are allowed at both of the ends. Like a linear queue & a circular q

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