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

Program to change date format, Write a program that accepts a date from the...

Write a program that accepts a date from the user in the form mm/dd/yyyy and then displays it in the form month dd, yyyy, where month is the name of the month. Enter a date (mm/d

Matlab error, n2=2:100; t=3; while t { g3(t)=(1/2)*(0.63)*(0.8....

n2=2:100; t=3; while t { g3(t)=(1/2)*(0.63)*(0.8.^(n2)); t=t+1; } g3(1)=0; g3(2)=0; what is wrong with the code above? it tells me that line: g3(t)=(1/2)

Python , Python Programming hmw help!! Write a program that ask the user to...

Python Programming hmw help!! Write a program that ask the user to input the followings: number of shares, stock price, and broker commission. Last month jim purchased some stock

Shell script, find value of nCr using function

find value of nCr using function

Advantages of visual basic programming language, Advantages of visual basic...

Advantages of visual basic programming language Visual Basic is an exclusive selection language published by Microsoft Company, so programs published in Visible Basic cannot, e

Asp.net and c#, The method should call getAllCities() and return the index ...

The method should call getAllCities() and return the index of the City that has the shortest (euclidian) distance to the. longitude and latitude passed as parameters

What is hiding a method? explain, Question 1 Explain the three traits of O...

Question 1 Explain the three traits of Object Oriented Programming Question 2 Write a note on (a) Assignment Operators                             b) Bitwise Operators.

Program to produce the given output , Given a file named maze1.txt whose co...

Given a file named maze1.txt whose contents is 1 0 2 2 1 2 3 0 3 2 2 1 2 0 2 2 3 0 1 1 3 1 0 0 2 0 3 0 0 1 2 0 3 2 2 0 1 2 3 2 1 0 0 1 1 0 0 0 your program when run as a.out

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