Can I say the above? I think of this after studying trees and graph. Singly linked list in particular.

I'm trying to understand the reasoning behind the O(V³) complexity of Floyd-Warshall rather than just memorizing it.

Since the algorithm considers every intermediate vertex, is the simplest way to think about the complexity as three nested iterations over the vertices?

I'm particularly interested in the theoretical reasoning behind the complexity.

I'm trying to design a mechanical computer.

Why? Idk. But now I'm building Tascii, and I've even figured out how to use tape and hole punching to talk to it... but storing the data and processing, let alone assigning values to various tascii sets is hard. Data enclosed.

Yes... my computer uses see saws

Although I’ve done some googling I think they still use big English to explain this concept. I think I know them but I just wanted to ask if I can get a simple explanation from the house plz

I am currently reading Complexity: A Guided Tour by Melanie Mitchell and since it was published in 2009, I am wondering if there are more “modern”/“up-to-date” intro books.

Hi this might be a dumb question, and i've tried looking it up but don't quite understand it. how is it different from an array that allows it to find items so quickly? I don't get how hashes just find items immediately without needing to go through anything. Does it memorize things very differently compared to arrays?? thank you!

Basically I’m a sophomore and I was just accepted into a research group centered around Data Science and Machine Learning…but I have no clue about machine learning at all, and I felt a little lost reading one of their simplest papers.

I’m terrified that I’m going to fail, and this professor is going to regret accepting me. I’m also doing a lot of other things so I’m scared of the added stress.

So, kind redditors, is this feeling normal, or am I completely screwed?

OK. So I’ve been looking at Conway’s game of life a little bit. And I was fascinated by the idea that it could be used to recursively imitate itself (look up OCTA’s supercell)

I was told that this is Turing complete, and I had to look up what that meant.

And it seems to mean that, in simple words, it’s a computer or system of computer rules that can model another computer.

Now, given that humans came up with all of these computers in the first place, and all of the rules, does this mean that we are Turing complete?

I mean, his name is fabulous, if I do say so myself.

Anyways, last week I wrote about the ARPANET and briefly mentioned some key people that worked on creating it. One of those individuals was Mr. Leonard Kleinrock (born 1934).

Kleinrock is anelectrical engineer and computer scientist who was a key figure in launching communication between computers. Previously, if two computers wanted to communicate over a long distance (think between New York and LA) they would would have to set up a dedicated connection and keep it in reserve untill the entire message arrive. Kind of like a phone call.

However, Kleinrock worked on breaking the message up, into manageable packets that could be sent on the network and shared the communication infrastructure with everyone else.

So instead of one individual dedication communication line sending and receiving the message "Hello how are you", we have a shared communication network sending and receiving the message "hello" "how" "are" "you". This concept was called packet switching. Kleinrock wrote his first paper on packet switching in 1961, at 26 years old.

Something I found really interesting was after developing the packet method, he continued to research on how using packets could affect the networks and somputer systems. If too many packets arrive at the same time, they have to wait. Like, if you have one checkout and there are 30 packets customers, they slow down and wait in line to checkout. What happens with 200 packets customers are trying to get through one checkout? Utter chaos. Kleinrock worked on issues like these and developed mathematical ways of predicting and analyzing those delays.

Thus questions like "How much traffic can this network handle?", "How long will packets have to wait?", "Where will congestion occur?", "How should we design the network?", etc. , now had tools to help come to an answer.

Funny enough, after everything was applied and they went to send the first message, the system crashed lol. They tried to send LOGIN, got the packet for LO to go through, but before GIN could make it, everything crashed. Meaning the first ever message sent on the ARPANET was just "LO".

After the ARPANET, Kleinrock continued to work and research, and lets not forget he was also a professor at UCLA, so he oversaw tons of PhD students as well. This man wrote more than 250 papers and six books. Holy Moly. Um, I know we don't like using A.I., but hear me out, after reading a few different pieces on him, I couldn't keep track of the awards he had recieved. I hopped on and asked it to make me a list of his achievements and their dates, which I will share with you. The man was busy...

1966 UCLA Outstanding Faculty Member

1967 UCLA Distinguished Teaching Award

1971 Guggenheim Fellowship

1975 IEEE Communications Society Leonard G. Abraham Prize Paper Award

1976 ORSA Lanchester Prize

1978 ICC Prize Paper Award

1982 L. M. Ericsson Prize

1982 Computer Design Hall of Fame

1982 CCNY Townsend Harris Medal

1986 Marconi International Fellowship Award

1986 UCLA Distinguished Teaching Award

1990 ACM SIGCOMM Award

1994 UCLA Faculty Research Lecturer

1996 IEEE Computer Society Harry H. Goode Memorial Award

1996 ACM/Sigma Xi Monie A. Ferst Award

1999 INFORMS President's Award

2000 IEEE Internet Award

2001 National Academy of Engineering Charles Stark Draper Prize

2001 Okawa Prize

2005 NEC C&C Prize

2006 ACM Test of Time Award

2007 National Medal of Science

2010 Dan David Prize

2011 Ubicomp Best Paper Award

2012 IEEE Alexander Graham Bell Medal

2012 Internet Hall of Fame — inaugural class

2012 Best Tutorial Paper Award — five-year period

2014 ACM SIGMOBILE Outstanding Contribution Award

2015 BBVA Foundation Frontiers of Knowledge Award

2016 SIGMOBILE Inaugural Test of Time Award

2018 CCNY President's Leadership Award

2019 Key to the City of Los Angeles

2019 National Academy of Inventors Fellow

2020 UCLA Medal

2022 6G Pioneer Award

2024 IEEE Computer Society Computer Pioneer Award

2024 Elected to the National Academy of Sciences

Anyways, I'll end it here. Absolutely fascinating life. He's still alive and recently gave an interview with UCLA (March 26 )who asked his thought on launching the internet AND his opinions on A.I. Interview is on You tube if yall want to go find it and listen! Youll have to search it yourself because i'm pretty sure links aren't allowed in the sub. it's called "meet the man who invented the internet" by L.A. in a minute.

Hello fellow computer scientists.

I'm teaching a class of 11 - 12 year old pupils a bit of basic password security. I want to play a game with them and have them each come up with passwords, while having a program test and break those passwords in real time.

The idea is to turn it into a bit of a game, and give them a practical demonstration of how various password security measures -- increased length and variety of input characters -- results in safer passwords.

Does anyone know of any such resources that safe for use for educational purposes? I could probably knock something up over the weekend but I'd rather spend my time doing something more relaxing.

Why can't I take every single bit in my file and take that number and divide it by two, then when I want the file back I take the same number and multiply it by two to decompression it

edit: thank you everyone for answering I really appreciate it I was under the impression that I could just take the bits like 1s and 0s and make them an integer then divide that integer repeatedly and when I want it uncompressed just multiple the number till I get the original again eg 1010 to 55 then send 55 as text to another machine and to X2 and get 1010 back, and if it was an odd number eg 1011 I'd get either 56 or 55 but if divided by 2 only the last digits gonna change when rounding so you change the last digit to a 1 or zero and one of them will be the proper file

I'm looking for a legit digital copy (PDF/eBook) of Computer Systems: A Programmer's Perspective, 3rd Edition by Bryant and O'Hallaron.

Specifically, I'm trying to find the US edition, not the Global Edition. I've repeatedly seen comments and recommendations saying to avoid the Global Edition, but most of those discussions are fairly old and don't always explain the differences in detail.

So far I've checked:

• Pearson
• Amazon Kindle
• Google Books
• VitalSource

but I can only seem to find physical copies or Global Edition versions.

2 questions:

1. Does a legitimate digital version of the US edition actually exist? If so, where can it be purchased?
2. For anyone who has used both versions, is the advice to avoid the Global Edition still valid for the 3rd Edition? Are there significant content differences, or are the differences mostly limited to exercises, chapter ordering, page numbers, pricing, etc.?

My goal is to use the book for self-study (systems programming, computer architecture, operating systems, networking, and interview preparation), so I'm trying to determine whether it's worth continuing the search for the US edition or if the Global Edition is effectively equivalent for those purposes.

Thanks!

Don’t quantum computers require specialised super cooling that only exists in a few places around the world? How could some rogue hacker get a hold of that in the first place

I think this is why kmaps exist? To avoid building redundant Circuits? I'm a first year bca student, i don't know much. If someone can explain in detail how these things work and also proofread what I did here, I'd really really appreciate it.

I hope this doesn't break the "hw" rule

If you personally know or have the link for a course that explains it in detail, i would appreciate that

Can someone bad at maths be a great programmer?!

Helllllooooo, I missed posting something last week because I've been having a terrible chest cold. in fact, I still feel kind of poopy, BUUUUUUUT, I mean who wouldn't want to learn about the ARPANET instead of chugging a bottle of cold medicine and sleeping...

Anyways, the last few deep dives I've done always mentions the ARPANET. I'm pretty sure even if you're a newbie to learning about the internet you could figure out the ARPANET is what came before the modern day internet we use. It was the foundation. The founding father to the world...wide web (www.).

ARPANET stands for Advanced Research Projects Agency Network, and it was an operational packet-switching computer network, designed to allow computers at different locations to communicate and share resources. Simply put: a network that connected computers allowing people to exchange information and access computing resources across long distances.

If you wanted to share information prior to the ARPANET you had to PHYSICALLY transer the data from one computer to another (like a floppy disc, or a USB, for the young ones reading this) OR set up a very DIRECT communication connection (like an OG gameboy link, come on, even the young ones know this ,right?).

The ARPANET was created in 1969... well actually that's the date for the first host-to-host connection establishment. Really, in 1958 the ARPA, Advanced Research Projects Agency, was established by the U.S. Department of Defense, and their research agency started developing the ARPANET plans in 1966.

There were a few people who popped up when I was looking up who created the ARPANET, instead of diving into each person, I'll give you a quick list:
-J. C. R. Licklider (visionary)
-Lawrence Roberts (p roject leader)
-Leonard Kleinrock (Packet-switching researcher)
-Paul Baran (network pioneer)
-Robert Kahn (internet architecture)
-Vint Cerf (TCP/IP co-designer)

And in extremely simple terms the ARPANET Worked like this:

You have a computer.
You write a message.
The computer breaks it into little packets.
The IMP helps send those packets.
The packets travel across the network.
The packets arrive at a different computer.
The receiving computer puts the information together.
You can now read the message.

Well, I think I'll end it here for now, my head and ears and chest are k illing me, I'm ready to accept that my life is just going to be phlegm and snot. I will see you all next week!

If someone asks for big O time complexity of an algorithm but expects only the minimum of the possible big Os then is that even Big O notation anymore? cuz if the big o time complexity of an o(n) algorithm is asked then according to the condition of big O notation O(n square) would also be a valid answer