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

.net windows services, .NET Windows Services But Enthusiasm has an amazi...

.NET Windows Services But Enthusiasm has an amazing record of beginning overdue but finding up easily. This is real in situation of .NET too. Enthusiasm put their best men at

Program for deleting nodes from the binary search tree, Problem: This...

Problem: This assignment is about deleting nodes from the binary search tree. You need to use given sequence to construct a binary search tree and then delete some nodes from

Shell script to check a given number is palindrome or not, Normal 0 ...

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

Write a program to draw the fish, Write a program to draw the figure shown ...

Write a program to draw the figure shown below. the program must provide: a. Close the fish's mouth slowly (at least 5 moves from the original position to close the mouth) b.

Secure programming environments, 1. A readme.txt file with: a. Instructi...

1. A readme.txt file with: a. Instructions on how to compile and run your client and server code on the command line. (Also provide shell scripts if the commands are complicated

Program to records name-bounty and difficulty for ten target, You have been...

You have been employed by a bounty hunter to create hit list (yes... you better do this right). Create a Hit List program that can records the name, bounty, and difficulty for ten

Silver light uses wpf to provide included web handles, Silver light uses WP...

Silver light uses WPF to provide included web handles Microsoft Technologies Silverlight uses WPF to provide included web handles similar to Adobe Display, but with more focus on a

Create a reservation system, Villa La Fourche Ltd is a small family busines...

Villa La Fourche Ltd is a small family business situated in the East Coast of Mauritius, more precisely Trou d'eau Douce.   The compound comprises of 6 independent villas, each of

Example problem of modularity, Example problem Imagine that  you  requ...

Example problem Imagine that  you  require  to create  a robot  that  will  roll up  close to a light  lamp  and  stop  a fixed distance from it.  The first question is, how w

Implement a two-dimensional table in prolog, Implement a two-dimensional ta...

Implement a two-dimensional table in Prolog. Your program will contain: An insert_entry predicate that takes a table, row, column and an entry and inserts the entry at the g

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