We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
from PART TWO - DATA STRUCTURES
Published online by Cambridge University Press: 05 June 2012
The main application of this chapter is algebraic expression evaluation. This is a classic and important problem. An algebraic expression containing single character operands and the four arithmetic operators is input as a string. When numeric values are assigned to each operand our goal is to be able to evaluate the arithmetic expression on the fly. The String representing the arithmetic expression is not known until runtime.
What makes this problem particularly interesting is that the core of the solution requires two stacks, each holding different types of data. The solution illustrates how abstractions (the stack in this case) may be utilized to provide an effective underpinning for the solution to a complex problem.
Algebraic Expression Evaluation
Problem: Develop a Java software application that takes an algebraic expression as an input string. An example of such an algebraic expression is (a + b) * c – d + e * f. After numeric values are assigned to each operand (values for a, b, c, d, e, and f), the algorithm must compute the value of the algebraic expression.
Input: A string representing an algebraic expression involving n operands and an n-tuple representing the values for the operands (i.e., numeric values for each operand).
Output: The value of the expression for the particular n-tuple of input operand values.
Solution of Problem:
1. Conversion from infix to postfix
The first step in solving this problem involves a transformation of the input algebraic expression from infix to postfix representation.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.
