Last Day to Withdraw From Classes

Tuesday, November 27.

If you haven’t been keeping up with the work, have a low grade average, or have missed a multitude of classes, please drop the class. I will issue a failing grade if your average is below a 60.

If the course has an associated lab, please drop that as well.

Unless you have a medical issue that can be verified by the Dean of Students, there are no extensions, extra work, or any other way for you to extend this semester.

CSC-220 HW7 Recursion Homework With Solution

Solution by A.C. Silvestri

Problem inspired by this article:

Due: Wednesday, Nov. 14, 11:59pm

Using recursive techniques only!

Write a function that takes as input a String and returns a “report” on the frequency of characters in the String.

ie input: “bbbdaacccced”

output: [{‘b’, 3}, {d, 2}, {c, 4}, {a, 2}, {e, 1}]

The “report” needs to be an ArrayList and each element of the ArrayList is a class that wraps a character and its count.  Much like a “BabyName”?

Do not give me a solution that doesn’t involve an ArrayList.

Of course, use the template.

CSC-220 Exam #2 Friday, Nov. 2

Let’s have our next exam covering chapters 9, 10, and 11 on Friday, Nov. 2. It will be an in class exam.

It’s a Closed Book / Closed Notes Multiple Choice Exam. COME EARLY TO CLASS AND BRING A PENCIL.

Go here for sample quizzes:

CSC-220 HW2 Arrays Assignment

Due: Friday, Sept. 21, 2018  11:59pm

Given two strings s and t, determine if they are isomorphic.

Two strings are isomorphic if the characters in s can be replaced to get t.

All occurrences of a character must be replaced with another character while preserving the order of characters. No two characters may map to the same character but a character may map to itself.

Example 1:
Input: s = “egg”, t = “add”
Output: true

Example 2:
Input: s = “foo”, t = “bar”
Output: false

Example 3:
Input: s = “paper”, t = “title”
Output: true


Incorporate the Project Template for those writing a command line program.  CSC-112 graduates can write a GUI to do this problem for extra credit.  Don’t forget that knowledge. 


Only use the material up to and including Chapter 7 on single dimension arrays.  If you include data structures that are beyond what we covered, then you will be asked to demo your code to class and explain its operation.


To convert a string to an array, use the String .toCharArray() method.

CSC-220 Chapter 7 Searching and Sorting Examples

Sorting and Searching V1:

Sorting and Searching V2 using Arrays methods:

Sorting Using BinarySearch routine (updated 9/17/18):

String Sorting:

String Sorting V2 With Interfaces and Lambdas

CSC-220 HW1 (Emirp)

Let’s do problem 6.27 (Emirp) shown here:

DUE: Friday, Sept 14 11:59pm

Here is a gist of the solution to 6.26 discussed in class:

Incorporate the Project Template for those writing a command line program.  CSC-112 graduates can write a GUI to do this problem for extra credit.  Don’t forget that knowledge. 

The template provides a way to run the code over and over again without having to restart the program.  For each run, prompt for the starting point for the emirp analysis and how many emirps you want to find from that starting point.

CSC-220 – Supplemental Video Course Series

Optional resources, but highly suggested supplements for this course.  I’ll be using these video series as a supplement to my lectures this semester:

These courses can be purchased for as little as $9.99.  Not bad!

Links and Resources for Java Courses

Liang 11th Edition Resources

Common Resources

Sign up for a GitHub Account

If you going to be a programmer, then github is a site you’ll need to use.

Go here: and create an account for yourself.  We will be using github for homework submissions.

In particular the part of github we’ll  be using is the gist function located here:

You can submit multi-file projects under just one URL! You also have a record of all your work in one convenient location.