Quick Thoughts on Test 2 and FSA

Got back test 2 and the recent problem set. I was generally happy with the marks which was good. As the semester is coming to an end it seems like all the work is starting to pile up.

This week we've continued to look at regular expressions and finite stat automata. The idea is that we can use regular expressions as a way to express a language. We can design our own language to with different alphabets. We looked at some examples looking at binary numbers containing even or odd number of zeros. The language can further be manipulated by applying principles such as commutativity or distributivity to the regular expression to create another regular expression.

We looked at some DFSAs where we created a machine which would take in a string and would be able to tell us whether it was a valid string by traverserving between the states. We say an example where we created a machine that accepted a binary string and would enter an accepting state for an even number of 0's. It seems the hard part is how to construct a machine for a particular collection of strings; all won't be as obvious as the binary number example we looked at. We need to make sure it can correctly judge all strings of that language and properly determine which are valid and which aren't. It seems to that we need to derive some state invariants and transition functions to create a correct machine.

Also a quick thought; I've went to the TA general help hours a couple of times and I've found them pretty helpful. I think going to them helped my understanding a lot for assignment 2 as well as test 2. I would suggest going to any students needing a bit of help!

Test 2 Thoughts and Formal Language/Regular Expressions

I was pretty happy with Test 2. So hopefully that feeling stays once I get the mark back as well. I'm just a bit worried about question 3. I'm not sure my loop invariant was correct; and didn't really use it as part of my proof like I probably should have.

Today we continued working with Formal Languages and Regular Expressions. So far things have been fairly simple; regarding the operations and definitions. Just the klene star (*) has been a tad confusing so far. We also saw an interesting example of the regular expressions in the form of a finite state machine.

Assignment 2 and Test 2

Last week was the due date for assignment 2. I thought that assignment 2 was significantly harder than the first. I had a lot of trouble with a couple of the questions particularly the Ternary Tree one which was carried over from the first assignment. I spent a lot of time drawing up trees and trying to push out a formula with not a lot of success. Monday before the due date I went to the TA help. They helped push me in the right direction, but I'm not too confident in my answer. I'm interested in seeing the solution for it.

This coming Friday is the 2nd test for this class. I'm hoping it isn't too hard/different from the examples seen in class and in the notes. It seems like every week there is something for this class. I do like the fact that the final is worth just 35%, but I think that 3 assignments, 6 problem sets, and 3 tests is a lot of work for a half-credit course.