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

Class Project, I need help getting started with a class project of creating...

I need help getting started with a class project of creating a project in the Perl programming language. I was thinking of maybe doing an employee directory

Adding new features to a simple shell implementation, You will be working o...

You will be working on creating both a realistic project environment and on adding new features to a simple shell implementation provided in shell.tar.z. After you un-tar it, let's

Dating game program, You are to write a program that determines the day of ...

You are to write a program that determines the day of the week for New Year's Day in the year 3000. To do this, you must create your own date class (MyDate) and use the following i

Reader-writer problem, The reader-writer problem can be stated as follows: ...

The reader-writer problem can be stated as follows: A shared memory location can be concurrently read by any number of tasks, but when a task must write to the shared memory locati

C# xna game project, I need to finish my game project within two weeks usin...

I need to finish my game project within two weeks using XNA. Would you guys can help me to finish it? Thank you

Program to present main frame contains of button, The program presents main...

The program presents mainframe contains two button new user, existing user PART ONE: CLICKING ON NEW USER New window appear contains: text field represent username,

Type of linear programming - dea, Type of Linear Programming - DEA The ...

Type of Linear Programming - DEA The Express Dry Cleaners currently has four locations in the Chicago area and willing be opening the fifth in the very near future.  Mr. James,

Write a function to draw backbone of the protein, Write a function drawCA(a...

Write a function drawCA(aname, coords) that uses the plot3 command to draw the C α backbone of the protein. When calling this function, you should pass in the aname and coords var

Code a simulation of image compression , Your task will be to code a simula...

Your task will be to code a simulation of image compression based on the approximate low rank structure of the set of image patches. You will write functions .code = my block compr

What is the switch statement, What is the switch Statement? This is a dif...

What is the switch Statement? This is a different form of the multi way decision that It is well structured, but can only be used in certain cases where: 1. Here, Only one var

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