Expression Tree, Programming Languages

Assignment Help:
For this assignment you will read a file expression.txt and create an expression tree. The expression will be a valid infix expression with the all the necessary parentheses so that there is no ambiguity in the order of the expression. You will evaluate the expression and print the result. You will also write the prefix and postfix versions of the same expression without any parentheses.

In an expression tree the nodes are either operators or operands. The operators will be in the set [''+'', ''-'', ''*'', ''/'']. The operands will be either integers or floating point numbers. All the operand nodes will be leaves of the expression tree. All the operator nodes will have exactly two children.

The outline of your program will be as follows:

class Stack (object):

class Node (object):

class Tree (object):
def __init__ (self):

def createTree (self, expr):

def evaluate (self, aNode):

def preOrder (self, aNode):

def postOrder (self, aNode):

def main():

main()
The function createTree() will take as input parameter an infix expression with parentheses as a String and create an Expression Tree from it. Assume that the expression string is valid.

You will take the expression string and break it into tokens. There are four different kinds of tokens - left parenthesis, right parenthesis, operator, and operand. When we read a left parenthesis we are starting a new expression and when we read a right parenthesis we are ending an expression. Here is the algorithm that you will use:

If the current token is a left parenthesis add a new node as the left child of the current node. Push current node on the stack and make current node equal to the left child.
If the current token is an operator set the current node''s data value to the operator. Push current node on the stack. Add a new node as the right child of the current node and make the current node equal to the right child.
If the current token is an operand, set the current node''s data value to the operand and make the current node equal to the parent by popping the stack.
If the current token is a right parenthesis make the current node equal to the parent node by popping the stack if it is not empty.
For the input file this is what your program will output:

( ( 8 + 3 ) * ( 7 - 2 ) ) = 55

Prefix Expression: * + 8 3 - 7 2

Postfix Expression: 8 3 + 7 2 - *

Related Discussions:- Expression Tree

Optimal solution, what is the optimal solution for this problem? Max 1...

what is the optimal solution for this problem? Max 1A + 1B s.t. 5A +3B 3A + 5B A,B >0

Genetic diseases, Genetic Diseases Problem Description Many human di...

Genetic Diseases Problem Description Many human diseases could be controlled by the knowledge of the gene's structure and pattern. The human gene could be represented by fou

Shell script to delete all files from system have size zero, Normal 0 ...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Calculate the sum of negative elements of specified column, Write a program...

Write a program that will generate 25 DWORD values in the range from +/-50 representing a two dimensional array of size 5 x 5. It should then display the array as a table (5 x 5) b

We are need of a prestashop expert, We are need of a PrestaShop Expert W...

We are need of a PrestaShop Expert We are getting a fresh design created for our Jewellery website. This job is in 2 parts 1. The website engine is PrestaShop as well as w

Write a script for explicitly display of values, Write a script called 'pro...

Write a script called 'prob1.m' that solves for the variables y, and z in terms of a user inputed x. The variables y and z are defined as follows: y = x - 30                when

What is multithreaded programming, Question: (i) What is multithreaded...

Question: (i) What is multithreaded programming? Lists the benefits achieved by multithreading your code in a program. (ii) What type of coding should be eliminated when d

Assignment about prolog, Hi I have an assignment for prolog languagle is ...

Hi I have an assignment for prolog languagle is it possible to get help

Java interfaces, Expertsmind brings you unique solution in java assignment...

Expertsmind brings you unique solution in java assignments Interfaces A program in the Java selection language is a fuzzy type that is used to specify a program (in the ge

Irc or internet relay chat application, Programming Project Specification: ...

Programming Project Specification: IRC or Internet Relay Chat is an application that lets multiple users communicate via text messages with each other in common "virtual" rooms.

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