5.1 Graph Traversals - BFS & DFS -Breadth First Search and Depth First Search

[@wirito]

Why do I like professor Abdul’s videos: 1) He speaks clear English. 2) Articulate, makes pauses. 3) Straight to the point. No unnecessary fillers. 4) More importantly, excellent explanations. Thank you sir!

[@numanshakir7255]

4

[@kushnayak1619]

@Pratyksha Maheshwari ok

[@MrKingoverall]

Of the reasons you pointed out, it's No.3 for me !! :)

[@midhileshmomidi2434]

Same

[@a-j19]

What can one ask for more than this!!!

[@ani.dimitrova]

I just realized that I've lived in a DFS-like way all my life. I start a task, then hop on to the next and quit the first one, then hop on to the third, then go back to the second and then to the first. How have I lived w/o knowing this until now :D Especially true when cleaning the house :D

[@manojkumar-lt6wk]

I think most humans live in a DFS way 😄. We deep dive into things forgetting why we actually started them.

[@suvraneelsaha8973]

you are not alone bruh

[@aswinp888]

😂😂

[@real_manikant]

😂 😂. Finally found someone who commented out my inner feelings

[@grandparick3176]

Your comment made DFS concept even more clear haha.

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*haha the other day i was travelling on a bus, and i saw someone else studying on the bus before his exam and he was watching your video the entire bus ride. Guess where this happened? Canada. Yeh you are popular everywhere because most of the prof are not meant to be profs.*

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Some Heros don't wear Mask Or Cap!! Peace !!

[@devanshtandon6314]

I have never honestly wasted time writing a comment on youtube before. However, this dude is special and I wanted to take a break from the video just to write a comment thanking this guy for all the videos he is making. Can't say it any more times but WE NEED MORE PROFESSORS LIKE HIM.

[@ShubhamThakur-lq5jf]

Thank you for your time Devansh SAMA!

[@moustafah1]

This is life saving !! I am not even looking at my lecture notes! They are so complicated! THANK YOU SIR! By the way, I am in Sweden, Chalmers University! Everyone watches your videos!

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I think we fall in love with educational content creators/professors like this because they take us from a place of feeling totally stupid to a place of feeling hope for our future. It's s beautiful thing

[@sksoumik8749]

OMG... This is the best explanation of BFS & DFS available on KZbin.

[@johnleonardo]

Agreed! He was very simple with his explanation. This helps me a lot.

[@sheetaldeo2779]

Sadman Kabir Soumik yes😊

[@vaishalijoshi7642]

right

[@iichaine719]

@@vaishalijoshi7642 take a look to myCodeSchool to realy get the better teacher ever. this one is good, but the other one is juste magicien. he has the exact words

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@@iichaine719 i know buddy, that one is on whole another level sadly he doesn't upload anymore.

[@VictorChrispinSamson]

You just summarized 25% - 40% of the Chapter and it's Questions in 18 minutes. Thank you very much! Best fast-taught video on BFS and DFS!

[@sowbanmuhammad546]

This guy taught me something in just 3:45 minutes which I haven't understood in entire semester

[@JP-programming]

ABDUL BARI , I CAN TELL YOU THAT YOU KNOW WHAT YOU ARE DOING , YOU ARE A GREAT TEACHER. I RESPECT YOU SIR.

[@sujeshrajasekharan1651]

Though I was ignorant about either steps until I watched this video, I patted my back for having used DFS logic for an recursive algorithm to traverse through nested groups for an application I was working on. Kudos for such a detailed explanation and analysis.

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I am an Experienced software developer with more than eleven years of experience, i have never seen such a talent you have, you explain things in best possible way. In my almost 15 years of watching online tutorials i have seen someone who explain who can explain complex problems in simplest way possible, simply you are awesome :).

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I come from Taiwan and you are the best teacher I ever know.

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This channel is the most underrated channel about algorithm in KZbin. He explains really clear and easy to understand.

[@yunathanielkang]

This is the best explanation of BFS & DFS available on KZbin. WAY BETTER THAN MY PROFESSOR IN UCLA.

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This is sooooo cool! This is like hit the point DIRECTLY without any unnecessary nonsense! Just like a brave soldier hit to the emery heart quickly and sharply!

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one of the best professor ever, I got an A in data structure and algorithms by just watching his videos and go stretch to exam. I don't need to look at lecture node.

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This came in my recommendation out of nowhere. I still remember watching his all videos and clearing advanced data structures in sem 6 of engineering a couple of years ago. Students, just watch his video, makes notes, and give your paper, you’ll pass smoothly

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What do you do nowadays?

[@kameshparameswaranganesan6785]

@@neverfold14 comments on youtube for a living.

[@c.g.9436]

I usually do not comment, but this dude had explained traversals, which i was struggling to understand, in just 20 minutes. Thank you very very much!!!

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Hi Sir, I am from the University of Sheffield, UK and everyone here loves your videos. You are so much better than our professors. Please keep up the good work and god bless you

[@jeanalmonor6555]

There are certain things that I can barely understand when I am in class, but when I get tuned to your lecture everything seems very easy as "BONJOUR" for me. Thanks, I really appreciate your performance in explaining this course online.Wish you the best!

[@mukulgupta7251]

Someone give this guy an Oscar in the field of education!

[@ruthraramanan3407]

Thats not an Oscar. Thats nobel prize for teaching

[@mukulgupta7251]

@@ruthraramanan3407 that is why i wrote "In the field of teaching"!

[@ruthraramanan3407]

@@mukulgupta7251 Who gives an "academy" award to an actual academic person? Oscars are for people in Entertainment. This guy deserves the educational award i.e Nobel

[@prakhargupta1745]

not those cringe oscar comments in an educational video bruh

[@Vedranation]

In 18 minutes you just explained what my professor couldn't in 2 hours. Thank you

[@antor.morsalin]

Weird how a free videos on KZbin easily beats full fledge university courses for which we pay thousands of dollars.

[@omarabdelaziz226]

Hello sir, I just wanted to say thank you. For the longest of time i was very intimidated by the tree search algorithms and was putting them off. But you just make them seem so easy. Your explanation and the visualization of stack and queue while solving was a big help. Thank you so much you really helped someone today

[@JV-jc7ci]

I admire your natural ability to teach and make complicated topics seem so small and simple. HUGE RESPECT!

[@ruvixreyez]

Imagine if all kinds of professor teaches like this, it would be my grade is Straight A's

[@Nam_David]

For me, he is the best Data Structure Algorithm Lecturer I've ever met, everything is clear, on point, precise. Thank you for giving us a clear lecture Hope you alway be healthy Mr. Abdul.

[@yosifsharrak7585]

This is super helpful thank you!! Just a clarification, I believe there is a mistake on 13:56. When going from 3 to 2, add 3 back to the stack so the stack should be [1,4,3]. Then at 15:25, go back to 3 and then to 4. I got stuck here a bit, so I hope this helps someone.

[@ayushjain5941]

i think that too

[@savalalingeshreddy5539]

Yeah I also observed it

[@codeherk]

This true. The 3 must be added back because it would be suspended while exploring through 2

[@sheikhharis37]

There are also many mistakes in BFS

[@aidenigelson9826]

@@sheikhharis37 usually when one tends to object to someone's mistake, they present a problem, and a solution. If you saw any problems, please state them.

[@janhvinarayan1633]

he teaches so effortlessly n at the perfect pace the the pronounciation is so clear, for theory paper he's perfect

[@dynamicjainish]

In 5 Days I completed MY Algorithm Course And I Passed With BC Grade Thank You So much Sir

[@setuchandwar92]

@@thebot177 an engineer can do anything

[@Ed-gd5ec]

@@thebot177 today is my exam. And I started studying for semester day before yesterday. And I'm confident that I can clear my DS. (BTW, I'm Engineering student)

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yome fisseha Finished a semester course in 3 days. Sometimes you gotta do what you gotta do.

[@1337Alexlol]

It all depends on the exam. At my school in Germany, the exams are always the same more or less. For most exams if you just want to pass it with an okayish grade, you just need to practice the tasks of the exam.

[@V-for-Vendetta01]

@@thebot177 i believe he was trying to say, "i finished my algorithm course 5 days ago". poor english i guess.

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Well structured, good pacing, clear delivery and very articulate. I can't understand how some lecturers can make a mess of such straight-forward algorithms, yet on KZbin I find 18 minute videos that can teach them perfectly.

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This man charges $0 a year to teach us what we pay the university $10,000 a year to teach us

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@Alvin Benedict Is someone else paying him for his hard work, same as him charging money to us ? I don't think so. No offense

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You are paying the University to certify you that someone taught you even if it is not the university.

[@yushpi]

@Alvin Benedict You guys could also support him on Patreon, the link is in the description. Just because he doesn't start his videos with an appeal for patreon contribution doesn't mean it should be ignored.

[@Tonyfix]

$14K in my case

[@Tonyfix]

@Alvin Benedict Crumbles....

[@bbcuckoos]

Man's majestic. I love his teachings, the way he talks... Infact, everything.... Damn

[@Jared-Cruz]

Currently taking my Data Structures & Algorithms course, and whenever I don't understand a topic, I can find a video on this channel that explains it perfectly. Thank you for this channel!

[@jaykoranga4859]

this is what feels to be taught by a real teacher , earlier i was watching the tutorials of other youtubers , i agree they (youtubers) have the knowledge but having knowledge and be able to teach that knowledge in a way that is both simple and clear is a whole another thing. thank you Abdul Bari sir... i will watch all of your videos .

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I not only learn, but also enjoy your videos. Great job.

[@cje8887]

I landed here while trying to solve CS50 tideman. I have no math/logic/algorithms background, yet I immediately understood this exploration. Thanks for the video! I'll be back to watch the entire course in the future.

[@joao_vieira]

Don't usually comment videos but loved both explanations and examples. Makes it so much easier to understand! Thanks!

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You saved my life so many times. THANK YOU!!!! A lot of Jamaicans watch your videos.

[@abdul_bari]

Glad I could help

[@swapnilkale3952]

This is why I pay my internet bills. To be able to listen to great explanations like this. Thank you!

[@sumangautam1535]

I am studying Artificial intelligence in university of Tasmania and the lecturer is Chinese and I cant understand his voice but you explain with your clear voice and tone which help a lot .Thank you so much.

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the moment I see your tutorial while searching for a topic.. I know that I will grasp it for sure by the end of video.. cheers!!

[@LincyMcGabby]

I'm so grateful for this. Love your way of explaining. BFS & DFS for graphs seemed so complicated & hard to master in class, but I understood them so well & easily just by watching this video. 6 years later & this video is still SAVING LIVES💯

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Sir you saved my life I needed clear examples of the algorithms explained, you didnt give 1 hour lecture talking irrevelant stuff for exam, right to the point thx

[@Lionheart0212]

I’m a college student from China. Your video provides me a new perspective to understand bfs & dfs using queue and stack. And I do learn a lot from it! Heartfelt thanks:)

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Such a simple concept that my professor tried to explain in such a confusing way, thanks for clearing everything up! All of your algorithm videos have been super helpful! I would love to see some coding videos in the future, maybe?

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Checkout his dsa course on udemy

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Can't thank him enough, he is so inspiring and sharing knowledge for free. What a great human.

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I'm in my third year of college and tomorrow is my Data Structures semester final exam and the only reason I'm able to carry on is because of your teaching which is just phenomenal. Thankyou soo much sir!

[@keshavsinghal8546]

This is actually one of the finest videos I've seen on BFS and DFS.

[@pranavinissan]

That was really effecient explanation without irregular pauses and grammatical errors. Thanks a lot.

[@savi6545]

started watching the video after 4mins of watching this video, I felt the need to write a comment. This is very straight to the point. Clear. Simple. Love his teaching style. Thank you sir!

[@suprith35]

Sir you are great sir didn’t understand in uni whole semester but your teachings just understood everything in just 18mins this algorithms I am using in Artificial intelligence concepts sir thank you so much sir. I am MS student in Australia 🇦🇺 you are so much popular here as well sir

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This is my first time watching him, and I’m also diving into the vast ocean data structures and algorithms for the first time. His explanations completely blew my mind! 🤯 I used to think that DSA was complex and beyond my reach, but after watching this video, my perspective has completely changed. I now feel inspired and empowered to tackle DSA concepts for my future interviews.

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my folk here in Houston Texas are watching your videos too because our prof cant teach

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This is the best explanation of BFS & DFS available on KZbin. WOOW!!!!

[@leozhang1340]

this man is one of the computer science god teachers on youtube. Kudos!

[@nextrie]

Honestly, that man is the teacher of the year. Thank you for all your content!

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Watching this man instead of listening to my graph theory teacher who talks like an AI, gave me A+'s on both my midterm and finals

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seems you want to show off.

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atp i owe this man tutition money for how much i rely on his vids

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You are like an oasis in the desert. Thank you so much !

[@serafinanarda8034]

I'd like to have you as one of my uni teacher!! I'm not a native english speaker but you was so clear that it was not a problem. Thank you

[@yuzuftonmoy6898]

Thanks Mr.Bari .Today is my final exam of Data structure and algorithom.You got my back.

[@JoyDas-mi8ww]

Preparing for an job interview & you make that easy for me. I don't even have to open my book now. I believe I can solve any complex problem of this field. Thanks a lot sir. May GOD bless you.

[@rashedamlan8572]

BFS 5:38 DFS 12:15

[@jackjhones8950]

thnx 4 seva

[@ladenbin]

The hero we need

[@HM-sid]

Thanks 😁

[@siddharthr594]

Legend

[@karthikh8993]

Ur a legend bro

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The best teacher ever...whoever is removing his videos from utube...pls don't do this.🙏

[@amphetaminocid]

I wasted my time on other videos and non of them were really helpful. this one is so simple and so descriptive. thanks Abdul for this great video. please don't stop and continue with great videos like this.

[@debarshiroy2939]

you are an oasis in the middle of an desert for countless students. Thank you for being here with us

[@lanemacdougall5955]

Not one to write KZbin comments, but Abdul Bari makes the best algorithms/data structures videos BY FAR. He is my go-to for anything CS-related. His videos are the best study materials I can find.

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Thanks! 100% of necessary information, 0% of bs, memes etc. Awesome!

[@malikjehangir3337]

Mr. Abdul, U saved our lives! regards from Germany... best videos!!

[@rizthetechie]

In my first experience in a single attempt a video could give a clear understanding how DFS and BFS works.

[@pratyushkatre8246]

You are the best teacher for teaching of data structure ... I like your style and way to explore the things ... Thankyou Sir ❤️

[@nirwanramteke4806]

I am going to write all his statements, examples in my theory exam, thank u sir for creating good explanation. Greedy Method, Dijkistra algo, Bellman Ford Algo, LCS, NP complete, Knapsack Problem, BFS, DFS

[@Noobmaster69_bro]

His explanation is too good..and i even got a glimpse of why recursion can be candidate for dfs... then why stack for dfs and Queue for BFS...just an awesome teacher..God bless

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The best explanation that I ever watch till now, a concept is so clearly explained, thank you sir for your effort to reach us.

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I studied completely wrong dfs and bfs on utube from other channel and told my senior abt that she told me it's a wrong way and trust me i thought she is wrong and then i found this vdo sir u just saved me from failing tommorow , my senior was ryt ❤️

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Sir this is the first time I visited your channel,the way you explain are so fundamental and crystal clear that I don't think so I will ever visit any other channel for queries

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the goat of data structure lecturers

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Just bought his Udemy course - much more in-depth than my college course.

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Literally it would make more sense to swap the tuition cost to take my D&A course at my university with his Udemy course price.

[@ogbonnafranklyn]

OMG... After following through the first example, i paused the video, went back to solve the initial challenge that brought me here, before coming to complete the video. Never seen complexity demystified like this.

[@mattralston4969]

Thank you again for the lecture, this was very helpful to me watching again as I did not understand the variations in depth and breadth the first time. I am liking the binary tree example very much to show that the linear order of the nodes (their sort order) is arbitrary (no pun). There is so much content on this channel, very educational and clear. Thanks

[@ShawkyJames]

I have exam in 5hours and started learning the course. This is exactly what I needed, wish me luck lads. THANK YOU!!

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Amazing! Your explanation of the examples were very clear and easy to understand. Thank you for your post and time that you put into this. You are an amazing teacher.

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This clears things a lot & the moment I understood there was a smile in my face. Thanks a lot for making this happen.

[@nishanisha1266]

U are really excellent sir making us clear to understand ,and repeating the important points helps for better understanding No one can beat u in teaching data structures concepts ☺️☺️

[@ar9045]

what a gem. Thank you for the amazing service to humanity.

[@kshitijdumbre-re5jk]

00:00 Learn about breadth-first and depth-first search traversal methods. 02:11 Difference between breadth-first search and depth-first search 04:33 Breadth-first search is like level order traversal and Depth-first search is like pre-order traversal. 06:59 Breadth-first search completed 09:25 Breadth First Search (BFS) algorithm rules 11:42 Valid BFS and DFS traversal explained 14:00 DFS traversal of a graph 16:25 Depth-first search and breadth-first search have time complexity of order n.

[@mc811mc]

Professor got me through Discrete Optimization and Data Structures and Algorithms class. He's a boss.

[@HarshKumar-nh6be]

In 19 minutes we are able to understand BFS and DFS but how?? ABDUL BARI SIR: Just go for an try it is possible..) YOU ARE REALLY GREAT SIR..KEEP IT UP!!

[@piotrzaczek5942]

I procrastinated on implementing BFS & DFS for a long time due to lack of full understanding of the concepts behind them. After carefully watching your video I implemented BFS with performance better than 99.97% submissions on LeetCode and implemented incredibly shitty (but working!) DFS myself. Thank you for your contribution!

[@collincesilenou6757]

better explained than in my university class. Thank you so much

[@niresh8019]

6 months ago this was the most underrated vid.Now the valuation has been realized

[@Zo91709]

Great explanation of this concept. Really helps me to understand the code behind everything now. Thank you Abdul, Kind regards from Los Angeles

[@samanthasavoy5303]

Just wanted to say than you so very much for your clear explanation of this topic. I have been so confused with my textbook but you have saved me so much frustration. Thank you, thank you!!!!

[@lilac_amusement1115]

Every time before exam i watch only your videos which give me strength nd confidence that i can happily attempt the respective topic easily in exam 🙏😊...thanku sir!! Really tq so much✨✨

[@psroyalict]

Sir, You deserve more attention. These videos are very much clear and straight to the point. Simple English and simple Explanations. Very well done sir. Thankyou very much.

[@Ramel34]

Nice! There's just one important thing missing. When using depth first traversal you have 3 subcategories (pre-order, in-order, post-order). In pre-order. the vertex data is read first then it goes to the sub vertex. Whereas post order the vortex data is read last.

[@ajaudir8999]

Sir, you clear my doubts in graph traversals. Thank you a lot sir. A lot of loves from Malaysia.

[@datahat642]

There is a slight error in the video (14:05). While we explore vertex 2 we should suspend vertex 3 and push it into stack. This has been accidentally missed. Please consider the same.

[@ath2737fj]

everything at vertex 3 is visited so couldnt he take 3 out of the stack

[@SHREYAGUPTA-z8g]

yes possibly ... i noticed that too

[@pradyumnshirsath7671]

ha bro