I’m just under halfway through 2021 and I’m trying to understand which structures I should be looking for and when, although not being familiar with any of them, knowing what signs to look for is tricky. Does anyone know of or is able to type up a list of the common data structures and algorithms that were used during 2021 and which days they were used on?

Hey folks,

I'm a Full Stack Engineer with focus in JavaScript with around 2-3 YOE now. I've done freelance before, have shipped a greenfield application for a client as part of a consulting startup, and am currently part of a startup that just released an MVP within which I took care of quite a bit of features, new standards, etc. So if someone came to me with an idea for a business problem, I'd say I'm pretty certain that I can figure it out and help the client release it at least to an MVP stage.

All of my experience has come from working in high-speed startups with focus on pushing out an MVP and have worked in the smallest teams up to about a 20 man team.

However, I cannot for the life of me understand what the f**k is going on with Data Structures and Algorithms. I understand how to relate business needs and requirements to code but I can't get Data Structures and Algorithms at all.

Does anyone have any suggestions for me? I've tried reading through CTCI, Intro to Algorithms and I have no clue what's going on there. I find it extremely hard to relate those concepts into a business perspective.

I'm more than open to any suggestions if you think it helps.

Thanks!

There is this quote posted throughout internet:

>"It is better to have 100 functions operate on one data structure than to have 10 functions operate on 10 data structures." This quote is from Alan Perlis' Epigrams on Programming (1982).

Do you agree? Why and why not? I personally strongly disagree, because I would very much prefer having List, Vector, Map, Set, Maybe, Result, and 4 more data structures, each with 10 functions instead of just List with 100 functions. And it seems every single functional programming language I know is rather an example of former than the latter. The most bright example of latter I can think of is JavaScript which stimulates using dynamic arrays and hashtables for everything.

I’ve recently started UC Berkeley’s CS61B data structures and algorithms class. It has really cool resume worthy projects and I’m looking for someone (or many people) to grind through it with! Here’s the link

I don’t know how I got to that point of my studies , I feel like I don’t know coding to be in 300 lvl classes and it terrifies me to the point when I can’t eat and I can’t stop shaking . One of my classes will require to build a project with other people and I am scared they will laugh at me or kick me out for being bad at coding . Plus having only boys in my team also intimidates me … I am feeling so overwhelmed and just shitty and idk what to do..

many people online are emphasize so much on the relevance of the knowledge data structures and algorithm as a programmer. So it has left me wondering, if Its applies to one going into machine learning. having spent the last 3 months learning python, I dunno If I should take a detour and learn it before going on to study machine learning maths?

Thanks in advance for your time

I was thinking of starting to learn DSA and was looking for resources online.

So far, I've looked into these:

1. Algorithms and Data Structures EdX
2. Geek for geeks
3. VisuAlgo.net

I mostly like VisuAlgo coz i'm a visual learner (for the most part). I was wondering what resources for DSA do people on this subreddit love/trust the most.

There are a lot of resources on the internet on these topics. I just don't know what to select(as a beginner interested in competitive programming) in order to build a solid foundation.

I am absolutely overwhelmed. It doesn't matter if the resource is paid or not. I'm just looking for a structured plan as I'm tired of jumping from articles to articles and not seeing any knowledge gains.

Thanks in advance!

So, imma post again because I barely got any attention in my first post and I'm a desperate cry-baby! So, I need some advices. I'm kinda stuck in Data structures. I've understood the basics but when it comes to combining all the techniques to code something I get a lost and I'm up to a very frustrating point where anything I find is really basic (or same things over and over again) or too complex to the point I get unmotivated.. My question is, do I stick learning this good, or do I move on and understand as I progress? Because I know that this part is important to know well. Thanks!

Any good resources except CodeWars type of stuff? Because these don't seem to help me a lot for the moment

Hi all,

I notice we can also take Computer Science 201 at study.com to satisfy Data structures and algorithms(1). The only thing is that they teach it in Java, which i dont mind, but the DSA 2 course at WGU would be in python and so I dont wanna confuse myself or have room for disconnect because my foundation was in Java instead of python.

Is it more wise to just take both DSA courses at WGU instead since they'd both be in python?

or is it still okay to take DSA 1 (java)@ Study.com, then DSA2 (python) at WGU?

Im new to all this, so Thanks so much

I am trying to figure out what ABI makes available to application programmers in machine languages. An OS such as Linux provides ABI and API. Does ABI make accessible exactly the same functions and data structures that API does (except that ABI makes them available in machine language)? No more and no less?

Are kernel-space functions and data structures accessible by OS ABI? For example, Linux has some in-kernel functions and data structures which are not accessible by Linux API. For example, if I am correct, "kernel thread" can only be used inside Linux kernel, while "lightweight process" can be accessed at Linux API via "clone()". Are those in-kernel functions and data structures accessible in machine languages by Linux ABI?

Thanks.

Loved CS50 and was fascinated by these concepts. Was wondering if anyone has recommendations for courses I can do, or should I go straight to trying leetcode?

Full stack web dev with 1.5 yoe. Always excelled at take homes but not LC. I have tried to improve at LC for years, even when I was in college, but it has always been so much harder. Even now with practical work experience, I can’t solve even the easy problems, unless I use brute force only solutions and never complete the follow up. Same with interviews with live coding challenges. Struggle with not using brute force solutions and follow up mostly consists of them teaching me how to implement faster or less memory solutions.

I have tried YouTube videos, reading others efficient solutions/discussions, brushing up on my dsa class where we learned about similar things, but none of it seems to help.

How did you guys improve on LC? If you’re not able to either, I would just like to know I am not alone.

Title. It's easy to find on the internet how to structure your web dev project, or your data science project but I couldn't find any for data engineering project, can anyone share how you do it?

Hello. Hope you're all having a great winter break.

It goes without saying Data Structures is one of the most well-known courses at RPI. CS students can recall the course's hardships, heartbreaks, and hair-pulling homework. And as a student taking Data Structures this spring semester for the first time, I thought I would ask these students for advice, namely what students wished they knew when first taking Data Structures.

What's the best way to study for Data Structures? Is there an online course or YouTube video playlist that you found really helped? Perhaps you can recall the title of a book that helped as a reference guide? Maybe a resource at the library, or a method of studying that made homework/exams easier?

Of course, I am going to invest as many hours into the homework and studying for exams as possible. I am going to go to office hours as often as I can. I have already completed most of the C++ crash course on Submitty. Still, the more help I can get, the better.

Thank you in advance.

Edit: Thank you so, so much for all the advice! I honestly didn't think this post would yield this much attention. I have read all your responses and really do appreciate the time you all took in making them.

Have a CS degree but it’s been awhile since I’ve studied data structures, and I’m looking for the best online course to take to go back to the fundamentals. I have many saved to start but thought I’d crowd source here. Any in particular that stand out above the rest to those who’ve been in the industry for awhile?

I began taking a beginner Udacity course on Python (the name of which I'll add to this post once my headache goes away) a couple days ago after deciding I'm very, very tired of my current line of work. The beginning was easy enough: learn the syntax, learn the rules, learn their uses. Today I watched probably a dozen videos on sets, dictionaries, lists and whatever the hell else, and for the first time I retained abosolutely nothing. I decided enough was enough and I'm going to take a Python break for the rest of the day.

I do actually have a project in mind to start on once I get the basics, and I know that's a change of pace for this sub. I'm a former music teacher, and my project idea is a simple calculator, if you will, for generating the scale degrees given two input data. For example, if the user inputs

Starting Note: G

and

Scale Type: Major

the program outputs G A B C D E F# G precisely in that order. The plan is to add scale degree numbers, both types of solfege syllables, and whatever else I can cram in, but for now I want to focus strictly on note names.

After watching the data sctructure videos today, I realized that these structures are what I need to hang on to this information. (Note names would be strings in this case, right?) My issue is that I'm havibg trouble understanding each structure, the syntax involved, and how I even go about using and recalling these structures for output. Like, should I use a list here? A set? I plan to start from the beginning again either tonight or tomorrow, but in the meantime if there is one best answer for this project's purposes, I'd greatly appreciate some feedback. Do not write the code for me. I am not looking for answers. I am looking for advice, best practices and perhaps links to ELI5 resources.

I am a cse major and I’m currently taking data structures. This is honestly one of the hardest classes I have taken. I’m only on homework 2 and it’s only going to get more difficult. Will the classes after data structures be as bad or will it be somewhat better/ more tolerable?

Not sure if this is wishful thinking, but I'm really enjoying Ziglings atm, nearing the end, and want to keep exploring zig in the same format.

And it's everyone's (mine) favorite time of the quarter! SEC Market Structure Data Update!

Let's see how GME has been behaving when it comes to hidden orders, odd lots, and exchange volume.

Hidden Rate

https://preview.redd.it/dn1mikup7zv71.png?width=1199&format=png&auto=webp&s=d229c3d06f506c991c14df06042fcc7e57cbe3bb

The hidden rate is calculated as total hiden orders / total orders. This order type is used to hide large sized orders (generally), which hides the submitted quantity from the order book. It's also got other nefarious purposes, notably a HFT strategy called hide n' slide.

GME: The first thing to note is that the Hidden rate for GME has increased significantly since the Jan sneeze, and has remained high since. I generally use this metric as a proxy for institutional involvement as there's an exceedingly low probability that retail investors know or bother using hidden orders.

The hidden rate remains high coming into the last quarter, sitting within the 25%-30% band, which to me indicates institutions are still very much active when it comes to trading GME.

Odd Lots

https://preview.redd.it/vbbp9i7r7zv71.png?width=1207&format=png&auto=webp&s=b0ef0bad074f2a8b367545b19dd87d1819958357

Round lots are multiples of 100, odd lots are anything outside that. A previous post I wrote here goes into much more detail about HFTs use them for order shredding and how odd lots relate to the NBBO.

GME: Converse to the hidden rate, I use odd lots as a proxy to gauge retail interest in GME, as the majority of retail are likely buying their shares in odd lots. This allows us to track if there has been any interest lost.

Has there been? Nope. There's been a slight downward trend, but overall it's remained relatively stable at ~40%. Popcorn stock is much lower, but that's due to the fact it's "easier" to buy in multiples of even lots.

Exchange Activity

Below we have two charts, the first goes into GME's trade volume distribution as a % of 100, while the second has a basket of stocks for comparison's sake. *Please note the legend is inverse to the ord

Hi,

I've been unable to catch up what's going on in the course because I'm not that good. I can barely write programs in OOP Java, and I barely recall what log(n) and recursive are. It's still the first week of the semester, but I totally didn't know what was happening in the latter half of the last lecture this week. We were analyzing algorithms and adding up units of time per operation per line of code, then suddenly logs appeared with geometric and...

I think I'm going to do a crash course review of OOP Java in MOOC, I rented out some of the recommended books about OOP Java, I don't want to fail the course and I need to know how to help myself?

I want to learn data structures and algorithms soon but I am struggling to find a course that is interesting. I have moderate programming experience and have participated on open source projects and created my own projects.

I want to learn competitive programming to get some stuff on my resume and hope to "win" some competitions.

Is it too late to learn competitive programming to get a google code jam tshirt?

Can someone link me some good websites to learn.

EDIT: Why am I downvoted?

Hello, can someone explain what this line of code implies as a snippet from below code block?

c.length = filestring.length()-c.position;

I understand it as:

int variable "length" in data structure "c" assigned to the variable "filestring"'s length......And then the -c.position; part is really hard to understand to me, does anyone know what it means? Thank you SO much<3

the code block:

#include "Delete.h"
#include <string>
#include <fstream>
#include <iostream>
#include <map>
using namespace std;

struct contact {
    string name, adress, epost, birthday, others, phone;
    int position, length;
};

void Delete(){
    cout <<" Enter the name that you want to delete it"<< endl;
    string nametofind;
    getline(cin, nametofind);

    ifstream efile("contact");
    if(efile.fail())
    {
        cout << "Could not read from contact file, maybe there is no contacts" << endl;
        return;
    }

    string filestring;
    map<string, contact> contacts;
    map<string, int> positions;
    map<string, int> lengths;

    while (!efile.eof())
    {
        contact c;
        c.position = efile.tellg();
        getline(efile, c.name);
        if(c.name.length() == 0) break;
        getline(efile, c.adress);
        getline(efile, c.epost);
        getline(efile, c.birthday);
        getline(efile, c.others);
        getline(efile, c.phone);
        
        filestring+=c.name+"\n"+c.adress+"\n"+c.epost+"\n"+c.birthday+"\n"+c.others+"\n"+c.phone+"\n";
///////////////////////////////////////////////////////////////////////////////
        c.length = filestring.length()-c.position;
//////////////////////////////////////////////////////////////////////////////
        contacts[c.name] = c;
        positions[c.name] = c.position;
        lengths[c.name] = c.length;
    }

    try {
        contact c = contacts.at(nametofind);
        filestring.erase(positions[c.name], lengths[c.name]);
        ofstream ofile("contact");
        if(ofile.fail())
        {
            cout << "Could not open contact file" << endl;
            return;
        }
        ofile << filestring;
        ofile.close();
    } catch(exception e) {

I would like to see how LIVE professional poker players notes look like.

How their notes about their session look like?

Hand notes

Win rate notes

Table selection notes

Valuing their own game play for every session A, B, C etc.

How they process and structure all this data once it accumulates? Maybe after every session they review all their live hands and then they would chose the most interesting spots and the one they need to improve on and add them to another data base?

I have been always bad at keeping good records at school and university. In fact at two or 3 classes I was so bad at keeping pace with the lectures and making notes that I completely gave up. Sourced out the one of the best hand writers in class arranged a quick deal for the notes. And literally got better grades then her during tests etc. In fact I would try sometimes helping her during tests because I felt guilty. Without her notes there was no chance of achieving such a great results.

I can't afford same thing to happen in poker. I need to learn how to structure and process my own information otherwise I will never improve.

If by any chance someone would be willing to sale me high quality hand history data notes and every note associated with his poker career for 1 year aprox 800+ hours) how much I should pay him? It should be mainly 2/5 and 5/10 (the stakes I'm aiming at).

Hi. Could you recommend some books for data structures, algorithms and system design in python. I have enrolled for 2 courses on a site. Wanted your suggestions on the books. Looking towards a career change. It would be appreciative if you could help. Thanks.

Is it really important to know all DataStructures when it comes to Mobile Development(Kotlin)?, i know it’s important in general and helps build good logic and algorithm, i have hands on Data Structures in Java, but the fact should i pursue more or i can make it as an Android Developer without being so good in Data Structures ?

Hey reddit,

Been programming for a reasonable amount of years and I know Python, R, SQL, Matlab, (basic) C++, (basic) Java + FP Scala amongst others. I recently signed an offer to start working as a data scientist after the summer, for now I'm looking at areas I can improve before I start working.

My background is masters level non-CS so I haven't formally learnt data structures and algorithms so this seems like a good place to begin (other things like testing frameworks and extra cloud skills are also high on my list). I know the basics of the most important data structures (lists, sets, hashmaps, queues) and intuitions about their corresponding time/space complexity. They were needed for some advanced courses (e.g. discrete optimisation w/ C++) together with some sorting / search algorithms but here typically only what was needed was covered.

I do kind of reason about them while writing code but maybe actually formally learning about them would make me a far better programmer. Should I potentially just try and wing it with my current knowledge, what do you think? In the past I've always avoided self-learning these as I believed my time was better spent on extra math + stat than on DS&A.

If you believe it IS a smart idea, can you recommend some resources? I know I could more or less find an 'open sourced' university course and watch the videos and do the exercises but I'm mostly looking for something maybe a tad less rigorous and more hands-on.

I know it’s essential for internships and the major in general. I’m pretty dedicated and I’m wondering how difficult the concepts are.

I started doing 6.006, and I am halfway through it. It takes me time to understand but once it clicked, man I live for this moment. But this vanishes away once I counter a problem on leetcode for a specific topic I learned. I have this issue, I can't connect between what I learned and how to use it to solve a problem. Is there something I am missing or some tips to help?

Hi,

May I ask, what will be the best practice on creating a database tables that could support data that will be displayed in the menu? This is because I am aiming of maintaining which menu should be displayed to which user.

Thank you

Do I need to know these (advanced, imo) computer science skills to be a statistical programmer or a biostatistician?

I was on my way to getting a computer science minor in addition to my statistics major and just finished taking the intermediate programming (in java) course last semester. It...kind of kicked my ass.

Object-oriented programming feels so uncomfortable to me, and that course wasn't even considered a weed-out. However, the next course, Data Structures & Algorithms, IS considered a weed-out.

Lordy, if I just barely passed the supposedly "easy" intro class, I'm not feeling hopeful for DS&A, a class that many people fail. Plus, programming in Java generally makes me want to die. For some reason, it just feels so much harder to me compared to programming in R or SAS.

So I am asking for some advice and advisement on whether the computer science minor is worth it to continue, given the future careers I am interested in.

Thanks!

Last semester for CS111 you could watch any of the professors lectures no matter who you’re actually Professor was. I was wondering if the same would be true for data structures next semester. Thanks!

Do you know any (free) websites that explain interesting algorithms (e.g. sophisticated searches or diff) or data structures (e.g. to efficiantly map between line number <-> character position in an editable text editor document)? It should be understandable by "normal" persons without a doctorate in computer science.

I’ve recently started UC Berkeley’s CS61B data structures and algorithms class. It has really cool resume worthy projects and I’m looking for someone (or many people) to grind through it with! Here’s the link