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 to check a given string is palindrome or not, Normal 0 ...

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

Differences between user and kernel level threads, Question : (a) Many ...

Question : (a) Many systems provide support for both user threads and kernel threads, resulting in different multithreading models. What are the two differences between user

Define the if statement - computer programming, Define the The if statement...

Define the The if statement - Computer Programming? The if statement is an influential selection statement and is used to control the flow of execution of statements. One of th

I need to do coding for the last three question, i attached the assignment ...

i attached the assignment document only i need your help with following three parts: accessible areas, accessible cul-de-sacs that are all connected, entry-exit path with no in

Create hijara game application, Assignment is to create hijara game on any ...

Assignment is to create hijara game on any plate form, you can use any plate form you like or easy to you. For instance let's say you can use visual studio, game studio (Prefer to

Str_concat procedure, Write a procedure named Str_concat that concatenates ...

Write a procedure named Str_concat that concatenates a source string to the end of a target string. Sufficient space must exist in the target string to accommodate the new characte

insertion sort algortihm, Define a higher order version of the insertion s...

Define a higher order version of the insertion sort algortihm. That is define functions insertBy :: Ord b => (a->b) -> a -> [a] -> [a] inssortBy :: Ord b => (a->b) -> [a] ->

Program to compute mixing ratio, Write a program to compute: 1.)    Mixi...

Write a program to compute: 1.)    Mixing ratio, W=.622[Vapor pressure/(pressure-vapor pressure)] 2.)    Virtual temperature, VT=T(1+0.61 mixing ratio) = T(1+.61W) 3.)

Define a prolog predicate that asserts list, Define a Prolog predicate flat...

Define a Prolog predicate flatten(List, FlattenedList)  that asserts List  is any nested list of atoms and  FlattenedList  is the same list with the nesting removed. The atom [] sh

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