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

Shell script convert the given amount into words, Normal 0 fals...

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

What is an abstract class, What is an abstract class:   Abstract class is s...

What is an abstract class:   Abstract class is stated as an abstract concept that cannot be instantiated or comparing to interface this can have some implementation and interface c

Need help starting a project out, I''m doing a project for class in college...

I''m doing a project for class in college and im supposed to use today''s date and figure out how old i am in months, days, minutes, and seconds. My question is what is the beset

A Simple Distributed Computing Platform , You are asked to develop a replic...

You are asked to develop a replicator (client) that distributes a large job over a number of computers (a server group) on a single switched LAN (our BU04 lab). In this assignment,

Assembly, Write an assembly program that computes Fibonacci numbers 2-5. a....

Write an assembly program that computes Fibonacci numbers 2-5. a. Assume Fib(0)=0 and Fib(1)=1. b. Store Fib(2) in EAX, Fib(3) in EBX, Fib(4) in ECX and Fib(5) in EDX. c. Use a LOO

Prelude to Programming, How does a Case Structure differ from a Case struct...

How does a Case Structure differ from a Case structure program in pseudocode

Application in pascal language for free pascal compiler , Before I describ...

Before I describe what you are supposed to do, please remember that this programming assignment is NOT a group project. You are NOT allowed to do this with anyone else's help. This

Python, How does a program provide "input" to one of its functions?

How does a program provide "input" to one of its functions?

Develop a program on behavior of hospital personnel, A psychologist is inte...

A psychologist is interested in learning about the voting behavior of college students.  (4 points for each part.)Design a study which would yield data on this topic. a. state y

Pascal, Problem Solving 1. Write Pascal code that accepts as input the nam...

Problem Solving 1. Write Pascal code that accepts as input the names of the students, course work score and exam score for a unspecified number of students who have taken a subjec

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