Important Notice:

Practice-It will be discontinued as of November 1st, 2024. After this date, the website will remain online for a transitional period, but login will be restricted to University of Washington NetID authentication. This marks the next phase towards the platform's full retirement. Thank you for your use and support of the application over the years.

If you are looking for an alternative, a similar tool, CodeStepByStep, was developed independently by the original author of Practice-It, and is available at codestepbystep.com**

logo Practice-It logo

Main Page → Problems → Solve a Problem

evenSum

Related Links:
Author: Robert Baxter

Write a method evenSum that returns the sum of the values in even indices in a list of integers. Assume we are using a zero-based indexing where the first value in the list has index 0, the second value has index 1, and so on. The values in which we are interested in are the ones with even indices (the value at index 0, the value at index 2, the value at index 4, and so on). For example, if a variable list stores the following sequence of values:

[1, 18, 2, 7, 39, 8, 40, 7]

Then the call of list.evenSum(); should return the value 82 (1 + 2 + 39 + 40). Notice that what is important is the position of the numbers (index 0, index 2, index 4, etc.), not whether the numbers themselves are even. If the list is empty, your method should return a sum of 0.

Assume that we are adding this method to the LinkedIntList class as shown below. You may not call any other methods of the class to solve this problem and your method cannot change the contents of the list.

    public class LinkedIntList {
        private ListNode front;
        ...
    }
    
    public class ListNode {
        public int data;
        public ListNode next;
        ...
    }
Type your solution here:


This is a partial class problem. Submit code that will become part of an existing Java class as described. You do not need to write the complete class, just the portion described in the problem.

You must log in before you can solve this problem.


Log In

If you do not understand how to solve a problem or why your solution doesn't work, please contact your TA or instructor.
If something seems wrong with the site (errors, slow performance, incorrect problems/tests, etc.), please

Is there a problem? Contact a site administrator.