Tuesday, September 1st, 2026

Today has been a good day. I hardly slept last night and woke up early but my mind feels much clearer than the last few days.

Today I had Operating Systems and Algorithms. For OS, our homework today was a small program to implement SHA1. We are learning about system calls, so we were to use open and read. I haven't coded in C in a while so it was nice to be back in it! I still don't really understand the OpenSSL functions, but the most concrete thing I learned is that a hash function doesn't need the entire context at once. So, we read from the file a certain number of bytes at a time (e.g. BUFSIZ) and then run EVP_DigestUpdate each time. For all I know, there truly is a cryptographic animal that eats and digests numbers to spit out the checksum :).

Algorithms was pretty interesting, we talked about the general from of binary search and merge sort ("k-ary" search and "k-way mergesort"). For k-way mergesort, if k=n, then it is equivalent to heap sort! I like how Prof. Chen brought this up, as well as his insistence that we shouldn't readily accept things for how they are without truly understanding generalizations and tradeoffs. I also had never heard of the recursive multiplication of binary integers, which we'll talk about next class.

It is hot and humid in northern Indiana. After lunch after class and I was feeling the tired beginnings of bad thoughts in my head, so I decided to zone out for a while and do a hundred solves on csTimer. During this I listened to a lovely conversation between Joscha Bach and Wolf Tivy on (machine) consciousness. I also turned on the fan so I would stop sweating! In my zoned-out state I think much of the talk was absorbed/felt but not analyzed, so I don't have many notes to add. But it was nice and interesting to listen to.

my 98th solve (13.91) was cool because it was a double "pseudo" x-cross on yellow:
D2 B' D' L2 D' R2 U L2 D F2 D2 L2 B2 R U' R2 F R2 U' F2
not very good at psuedo-slotting yet but that is a huge area of learning.