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

System defined data types, System defined data types:- These are data t...

System defined data types:- These are data types that have been defined by the compiler of any program. The C language contains 4 basic data types:- Int, float,  char and doubl

Comp. sci algorithms, 1. develop an algorithm which reads two decimal numbe...

1. develop an algorithm which reads two decimal numbers x and y and determines and prints out wether x>y or y>x. the input values, x and y, are whole number > or equal to 0, which

Determine the complexity, 1)    The set of the algorithms whose order is O ...

1)    The set of the algorithms whose order is O (1) would run in the identical time.  True/False 2)    Determine the complexity of the following program into big O notation:

Non-recursive implementation of binary tree traversals, As we have seen, as...

As we have seen, as the traversal mechanisms were intrinsically recursive, the implementation was also easy through a recursive procedure. Though, in the case of a non-recursive me

Define queue, A queue is a, FIFO (First In First Out) list.

A queue is a, FIFO (First In First Out) list.

Define the term counting - pseudocode, Define the term counting - Pseudocod...

Define the term counting - Pseudocode Counting in 1s is quite simple; use of statement count = count + 1 would enable counting to be done (for example in controlling a repeat

How to measure the algorithm efficiency, How to measure the algorithm's eff...

How to measure the algorithm's efficiency? It is logical to examine the algorithm's efficiency as a function of some parameter n showing the algorithm's input size. Instance

Algorithm to sort a given list by quick sort method, Q. Write down an algor...

Q. Write down an algorithm to sort a given list by making use of Quick sort method. Describe the behaviour of Quick sort when input given to us is already sorted.

Efficient way of storing two symmetric matrices, Explain an efficient way o...

Explain an efficient way of storing two symmetric matrices of the same order in memory. A n-square matrix array is said to be symmetric if a[j][k]=a[k][j] for all j and k. For

What do you mean by hash clash, What do you mean by hash clash? Hashing...

What do you mean by hash clash? Hashing is not perfect. Occasionally, a collision occurs when two different keys hash into the same hash value and are assigned to the same arra

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