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Learner Reviews & Feedback for Unordered Data Structures by University of Illinois at Urbana-Champaign

518 ratings

About the Course

The Unordered Data Structures course covers the data structures and algorithms needed to implement hash tables, disjoint sets and graphs. These fundamental data structures are useful for unordered data. For example, a hash table provides immediate access to data indexed by an arbitrary key value, that could be a number (such as a memory address for cached memory), a URL (such as for a web cache) or a dictionary. Graphs are used to represent relationships between items, and this course covers several different data structures for representing graphs and several different algorithms for traversing graphs, including finding the shortest route from one node to another node. These graph algorithms will also depend on another concept called disjoint sets, so this course will also cover its data structure and associated algorithms....

Top reviews


May 6, 2022

Great Teacher, although there are still a lot that I need to learn on my own(I come from non-CS background), after hereing these lectures, I feel that I have already learnt a ton.


Jul 16, 2020

This course had good coverage on hashing, disjoint sets, graphs. This course will improve coding skills.

I'm happy with material, coding practices, quiz and projects.

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1 - 25 of 108 Reviews for Unordered Data Structures

By Lenin I

Apr 27, 2020

Let me be very honest with you. The course is really tough, you'll have to watch the lessons again and again and again, read the Challenges several times in order to really understand them.

100% worthy, beyond my expectations. Do not hesitate to take these courses, the material is excellent.

Now I feel very comfortable reading algorithms books, no fear at all.

My only recommendation for University of Illinois team would be to create a separate C++ Specialization as well, it would be the perfect complement for this training.

By Leonardo O

Aug 24, 2020


int main(){

std::cout<<"The Best C++ Courses in Data Structures Out There"<<std::endl;

return 0;


By Yuguang T

Oct 11, 2019

One of the best online classes I have ever had! That said, this is probably not a course for someone who don't know data structures already. I learned data structures and algorithms a couple years ago and had done many interview algorithm problems so this series of courses help me to review things I know in C++. Nevertheless, great course design, great material and incredible presentation by the instructor!

By Christopher M P

Dec 28, 2019

Quick, automatic grading is nice, but final challenge problems that require simply filling in a couple of lines, and not enough problems requiring one to write a function on one's own.

By David F

Aug 22, 2020

I was never that strong academically. In fact, I was a stereotypical jock. I remember I used to make professor Wade do my homework for me and then stuff him into his own locker, #103. After graduation, I went to work for my father's insurance company, selling door to door. I was on the road 6 days a week and it really started to take its toll. That's when I found this course, and finally everything clicked. After completing this course, I invented a new algorithm that could calculate the shortest path that visited each house on my route only once... in polynomial time! Not only was I able to sell way more insurance, but UICU made me chair of the computer science department. Thank you, professor Wade, for changing my life. I am so excited to have the opportunity to stuff you in your locker once again. In your words, "I'll see you there".

By Filipe D

May 11, 2020

I quite enjoyed this course (actually as 3/3 of the specialization). The topics delivery was clear and the fundamentals of the data structures were explained so that it was not only blindly using some C++ classes. It is also good to get a lot of code that you can afterwards go through. The coding assignment felt a little bit short in quantity of lines of code required. Nevertheless, I felt they captured the relevant concepts. In the quizzes, if you get something wrong, a good explanation is usually provided. The staff is also quite active in the forum (at least on the threads I looked for). A final mention to the fact the the materials are updated, including clarifications or errata. Quite good to know that there is care in improving the materials rather than just put the first version in Coursera and never touch it again.

By Ryan B

Oct 12, 2020

I only audited this course but still got so much out of it. The challenges are tough and the course covers data structures and algorithms in great detail while teaching you C++ code. This has been one of the best courses I have taken thus far.


Feb 1, 2023

This course is definitely one of the best C++ online courses!

The course contents is well-designed and the assignments are quite challanging.

Thanks Professor and his team for providing such a great course in Coursera.

By Venkatesh M

Aug 30, 2019

Excellent course! Looking forward to a more advanced course from the same course staff!

By Tomer B D

Oct 5, 2019

The lecturer is super excellent and super clear. I wish he has more courses here.

By Difan G

Jan 27, 2020

Some Terminology is way too unclear and inconsistent, creating a lot of confusion. So are the lecture videos. The course length and materials are at the right pace and volume. I hope the instructor can provide more detailed explanation on many specific points and tie back to earlier chapters. This is a good course, but definitely need a lot of polish.

By Aren T

Dec 26, 2019

An outstanding conclusion to this MOOC specialization. I have learnt a huge amount on this course, and the opportunity to do programming assignments where you have to make additions to a provided substantial codebase is a brilliant learning strategy. The exposure to this high-quality code gives you plenty to read/digest. Meanwhile, the quizzes are superb and consolidate learning, and the video lectures are excellent. All in all, brilliant; you both learn a huge amount about computer science/data structures & algorithms, and you also develop some serious exposure to C++. Thoroughly recommend this Specialization.

By Hadi M

Jun 22, 2022

Even though I have technically already taken data structures, I found this course and in turn the entire specialization super helpful. The professor is obviously passionate about conveying the ideas and does a great job of explaining why we would want to use specific data structures rather than just stating that these structures are used everywhere!

The fact that assignments are in C++ was also a huge plus for me because I have been trying to jump back into the C++ train. Furthermore, I cannot think of any other language that would be more suitable for implementing data structures.

By Helom B

Mar 1, 2020

Another exceptional course by Prof. Fagen-Ulmschneider. I had the pleasure of taking a class with him on-campus at UIUC and the online versions of his coursework do not disappoint! It was all very digestible and I learned a ton. I finally gained some invaluable experience with data structures and the algorithms we can apply with/on them after dabbling in a few other online courses that I felt were lacking. Thank goodness I came across the classes UIUC offered on Coursera! Looking forward to more courses from the professor and the UIUC team!

By Yuhan L

Aug 6, 2021

I would like to give it 4.7 start (but round to 5 star). It is very engaging and the projects add more fun to the class (although after you figure out what you really need to do, it seems a bit simple and less challenging). I do hope the teaching team can update the github soon and provide the code implementation for all the data structure. The reason that I want to remove 0.3 star is the absence of those code implementation, because I learn a lot from studying the source code.

By Jonathan M

Apr 8, 2020

This is a very practical course that also is sufficiently difficult for a MOOC. The examples require some time to work through but I gained a much better intuition about graphs, disjoint sets, etc. by completing them. The course videos are high quality (not just slides) and the professor does a great job of walking through all the examples. For anyone who wants to learn more about data structures, I highly recommend this specialization.

By Andre A M

Dec 30, 2019

Great (non-math proof) introduction to topics such as Disjoint sets and Graphs. It's a bit more theoretical than the other two courses and topics are covered at a high level with decent examples. Of the three courses, this one was more confusing and challenging at times. I'd definitely recommend this course as a good foundational stepping stone to other algorithm specializations on Coursera.

By Sayed H

Apr 19, 2021

Course material is great, however, there are things that could be made better.

The good:

1) The exercises are great.

2) Code snippets are well documented and are a great source to learn further.

3) Lectures are clear and very good.

The not so good:

1) Too many silly mistakes in the lectures.

2) Many code samples are talked about in the lecture but are not shown in the examples or in exercises.

By 郑韬

Jan 23, 2020

I recommend this C++ programming specialization to beginners who want to learn to program and understand various aspects of data structure. The professor is an absolute master I have ever seen to teaching lots of essential knowledge in such a short time. Besides, the teaching staff is so passionate and responds to every question quickly!

By Le T H

Jun 14, 2020

The course is getting better and better. The more i get used to course material and instructions, the quicker i learnt and worked through the exercises. I am glad that i am able to finish this third course and also the specialization and looking forward to applying this new knowledge in my work. Thanks to professor and all TAs.

By Bijoy K B

Dec 30, 2020

A lot was covered in this course about Unordered Data Structures. I was always afraid of Graphs data structure but after completing this course, I am very much confident about all the algorithms involved in Graphs. A great course to also learn about disjoint sets, and heaps. I am very much happy after completing this course.

By Oleksii S

Mar 29, 2020

Highly recommended course! The explanations are very clear and to the point. The exercises code is a bit complicated if used just for demonstration purposes, but instructors try to show applications of the covered topics to real-world problems (in a simplified way, of course), which is good.

By Nguyen D L

Oct 3, 2021

Very nice conclusion to the specialization. The last Programming project and challenge on graph (BFS) took me a while to figure out. I love the satisfaction of finally completed these problems.

I am looking forward to more classes from Professor Wade and UIUC.

Nguyen Le

By Ashutosh K

May 17, 2020

This looks like a compressed course and it is, but the beauty of this course is that it covers all the topics so well that you don't need to go through anything else. Yes, it would help if you have a background in programming and some idea about data structures.

By Christoph H

Apr 2, 2022

Especially after looking into other, similar coursera and/or online courses, I have to say that the course quality and teaching quality of this course and the other two courses, is by far the best. Thanks, it was a lot of fun & I learned a lot!