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

Matlab, want to do an image-mean. but image is and mean is so an error ...

want to do an image-mean. but image is and mean is so an error showing Error using ==> minus Number of array dimensions must match for binary array op. wat to do?

System flowchart, creating system flowchart for website

creating system flowchart for website

Rewrite the xhtml code, Below is an example of an invalid XHTML page. Your ...

Below is an example of an invalid XHTML page. Your goal is to rewrite the code so that: No deprecated/obsolete tags are being used All elements are nested correctly (i.e

Java string handling, Expertsmind brings you unique solution in java assig...

Expertsmind brings you unique solution in java assignments String Handling Series signifies a sequence of character types. It has set duration of personality sequence. Onc

Shell script to count of five character words, Normal 0 false ...

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

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] ->

Power of mobile applications, BACKGROUND: This assignment illustrates t...

BACKGROUND: This assignment illustrates the power of mobile applications. OBJECTIVES: 1. Mobile applications DESCRIBED TASK: This is a single part assignment.

Area under curve, Area Under Curve Write a program to find the area und...

Area Under Curve Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve be

Optimal solution, what is the optimal solution for this problem? Max 1...

what is the optimal solution for this problem? Max 1A + 1B s.t. 5A +3B 3A + 5B A,B >0

Design and implement program, Tamagochi were all the rage in the 90's as a ...

Tamagochi were all the rage in the 90's as a small toy that had limited functionality but modelled a pet. The "owner" could do the following • Feed the pet • Heal the pet

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