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

Define midsquare method, Midsquare Method :- this operates in 2 steps. In t...

Midsquare Method :- this operates in 2 steps. In the first step the square of the key value K is taken. In the 2nd step, the hash value is obtained by deleting digits from ends of

Analysis of algorithms, A common person's faith is that a computer can do a...

A common person's faith is that a computer can do anything. It is far from truth. In realism computer can carry out only definite predefined instructions. The formal illustration o

Algorithm to find maximum and minimum numbers, Give an algorithm to find bo...

Give an algorithm to find both the maximum and minimum of 380 distinct numbers that uses at most 568 comparisons.

Define a sparse metrics, Define a sparse metrics. A matrix in which num...

Define a sparse metrics. A matrix in which number of zero entries are much higher than the number of non zero entries is known as sparse matrix. The natural method of showing m

Conversion of general trees to binary trees, Taking a suitable example expl...

Taking a suitable example explains how a general tree can be shown as a Binary Tree. Conversion of general trees to binary trees: A general tree can be changed into an equiv

What is Oscillating Sort?, For the Oscillating sort to be applied, it is ne...

For the Oscillating sort to be applied, it is necessary for the tapes to be readable in both directions and able to be quickly reversed. The oscillating sort is superior to the po

Define min-heap, Define min-heap A min-heap is a complete binary tree i...

Define min-heap A min-heap is a complete binary tree in which each element is less than or equal to its children. All the principal properties of heaps remain valid for min-hea

Merge sort , What is the best-case number of comparisons performed by merge...

What is the best-case number of comparisons performed by mergesort on an input sequence of 2 k distinct numbers?

Write down a module to merge two linked lists, Two linked lists are having ...

Two linked lists are having information of the same type in ascending order. Write down a module to merge them to a single linked list that is sorted merge(struct node *p, stru

Searhing and sorting algorithms, how I can easily implement the bubble,sele...

how I can easily implement the bubble,selection,linear,binary searth algorithms?

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