A* Search

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  • เผยแพร่เมื่อ 25 มี.ค. 2017

ความคิดเห็น • 324

  • @NikosXouselas10
    @NikosXouselas10 2 ปีที่แล้ว +86

    Absolute legend. This dude has literally been more helpfull than I could ever imagine! Insane work!

  • @mostafakarimi1733
    @mostafakarimi1733 5 ปีที่แล้ว +59

    One of the best explanation of A* algorithm I've ever seen, Thank you Sir and I hope you create more videos about AI

  • @terrycamerlengo5492
    @terrycamerlengo5492 3 ปีที่แล้ว +5

    This channel with John Levine is awesome. What a great lecturer! Great channel! Thank you!

  • @mishalubich7141
    @mishalubich7141 3 ปีที่แล้ว +6

    Best A* tutorial for run-through! Others jump around (computerphile) too much, and its not easy to get a grasp of how we can run this algorithm by hand and how it actually works (abstracting away all the data structures).
    Thank you so much!

  • @iampujan
    @iampujan 5 ปีที่แล้ว +1

    Loved the video. Clear and Understandable. Thanks Professor John. Looking forward for more videos.

  • @whiningmachine
    @whiningmachine 2 ปีที่แล้ว +5

    Thank you for this explanation. You have no idea how many pages and videos I had to go through before somebody explained that the heuristic indicates the estimated cost to a goal node. I had no idea why we only added the destination node's heuristic to the total (and not the other nodes' heuristics along the path), and now I know. Thanks!

  • @zaid_marridi
    @zaid_marridi 6 ปีที่แล้ว +6

    Thank you for this simple and great explanation... You're simply the best at this.
    Clean, clear, easy and very informative
    What else could someone ask for?!!!

  • @nitinneo7
    @nitinneo7 4 ปีที่แล้ว

    The most coherent explanation of A* algorithm with an example. Thank you for saving our time and energy.

  • @LucasofAppalachia
    @LucasofAppalachia 6 ปีที่แล้ว

    Absolutely phenomenal explanation. Thank you for this.

  • @lianghaoquan
    @lianghaoquan 4 ปีที่แล้ว

    Thank you for this great video! Love your clear explanation and your voice!

  • @tollwutpinguin
    @tollwutpinguin 3 หลายเดือนก่อน +2

    Thank you for providing free educational content of such high quality! The world needs more lecturers like yourself

  • @dennissaluaar9103
    @dennissaluaar9103 5 ปีที่แล้ว +3

    I am studying an introductory course in Artificial Intelligence here in Gothenburg, this short lecture made the A* very clear to me. Thank you!

  • @555to_infinity
    @555to_infinity 4 ปีที่แล้ว +2

    Wow. Perfect lecture on A* search. Highly recommended!

  • @cuchuoisalay9263
    @cuchuoisalay9263 6 ปีที่แล้ว

    I would like to say thanks to you. Your tutorial about A* is very exciting!

  • @coxixx
    @coxixx 7 ปีที่แล้ว +122

    the best teacher on the web

    • @johnlevine2909
      @johnlevine2909  7 ปีที่แล้ว +16

      Thanks. Glad you liked it.

    • @abhishekravichandran6965
      @abhishekravichandran6965 3 ปีที่แล้ว +2

      th-cam.com/channels/M-yUTYGmrNvKOCcAl21g3w.html
      she is the best bruh

    • @runneypo
      @runneypo 3 ปีที่แล้ว +1

      @@abhishekravichandran6965 she has no video on a star though

    • @vakiljay8686
      @vakiljay8686 3 ปีที่แล้ว +5

      @@abhishekravichandran6965 S I M P

    • @heer1359
      @heer1359 3 ปีที่แล้ว +2

      @@abhishekravichandran6965 S I M P

  • @HafizAsimNawaz
    @HafizAsimNawaz 7 ปีที่แล้ว +2

    I love this man...... you rocked sir... hats off

    • @johnlevine2909
      @johnlevine2909  7 ปีที่แล้ว +1

      Thank you! Glad you found it useful.

  • @OsamaAlmas
    @OsamaAlmas 6 ปีที่แล้ว +7

    This is amazing, You deserve more subscribers!!!

  • @simongrome9073
    @simongrome9073 ปีที่แล้ว

    These videos are super helpful in explaining stuff I didn't get from my textbook! Thank you!

  • @husseinsylla4850
    @husseinsylla4850 ปีที่แล้ว

    Hello Sir,
    Best tutorial I have covered on A* algorithms. Clear and complete, include all explanations for f(n)=g(n)+h(n) and over-estimations of theoritical heuristics. Brilliant. Thank you so much.

  • @Peter-bg1ku
    @Peter-bg1ku 2 ปีที่แล้ว

    Your explanation is amazing. Thank you!

  • @KuliahInformatika
    @KuliahInformatika 2 ปีที่แล้ว +1

    I love the way you explain the algorithm... easy to understand...

  • @abdolvakilfazli2488
    @abdolvakilfazli2488 5 ปีที่แล้ว

    Insanely clear explanation. Hope you add more details about completeness, optimality and complexity

  • @nilsmartel2295
    @nilsmartel2295 3 ปีที่แล้ว

    you're a most talented teacher. Thank you

  • @cieslak4004
    @cieslak4004 5 ปีที่แล้ว

    THANK YOU! Greetings from Poland

  • @Geek-jx3gw
    @Geek-jx3gw 2 ปีที่แล้ว +7

    throwback 2 years ago, you helped me to pass my exam and understand this algorithm really well

    • @balochx
      @balochx 2 ปีที่แล้ว +1

      How's life?

    • @Geek-jx3gw
      @Geek-jx3gw 2 ปีที่แล้ว +1

      @@balochx Amazing

    • @balochx
      @balochx 2 ปีที่แล้ว +1

      @@Geek-jx3gw stay amazing!

    • @Geek-jx3gw
      @Geek-jx3gw 2 ปีที่แล้ว +3

      @@balochx i didnt know what to answer but, life is not organized or as i wanted but it is better now
      2 years before I was a stressed person, stressed about a lot of things including my future, grades, etc
      now, i am older and i changed into a better version of me i guess, less stressed, i love my struggles, i love to help people as much as i can, I’m trying my best to be good enough for me and my family
      so yeah life is amazing now🙌🏻

    • @balochx
      @balochx 2 ปีที่แล้ว +3

      @@Geek-jx3gw thank you so much for sharing. and yes, ups and downs are a part of life. no one is completely satisfied with his/her life, we just have to embrace it and strive for the good. helping people for no agenda brings out huge happiness.
      and it was nice knowing about your story. I love hearing common people rather than famous people who are faking everything.
      Stay blessed 🙌

  • @nethmagunathilaka41
    @nethmagunathilaka41 5 ปีที่แล้ว +1

    Best place to learn A*. U save my day!

  • @TheSophiaLight
    @TheSophiaLight 2 ปีที่แล้ว

    Clear, patient, simple. Thank you.

  • @ShinnyxAKAvincent
    @ShinnyxAKAvincent 6 ปีที่แล้ว

    very clear speech, awesome explanation. Thanks a lot!

  • @nihilrocks
    @nihilrocks 11 หลายเดือนก่อน

    Truly a godsend! Saved me 5 marks on my A levels 15mins before the exam. Couldn't have explained it better!

  • @tashijawed5472
    @tashijawed5472 ปีที่แล้ว +11

    Great Explanation, as always. Just want to add one thing. at 9:43 When we reached node G2 with a cost of 13, we will stop the algorithm and won't go further with "E" node. Why? because it uses Priority Queue, the algorithm will stop once it finds a Goal node with a cost "less than or equal" to costs of other nodes. And it makes sense!! because once you reached G2 with a cost of 13, even if you have another node with the same cost, there's no point in checking it because it will only add to the cost.

    • @peterlawrence3505
      @peterlawrence3505 4 หลายเดือนก่อน

      But if the heuristic was not admissible this would not be the case right?

  • @kuanghuang2773
    @kuanghuang2773 6 ปีที่แล้ว

    very clear, very smooth, I like the teaching! thanks!

  • @ecekucukpehlivan9779
    @ecekucukpehlivan9779 4 ปีที่แล้ว

    These videos are very educational and useful. Thank you so much!

  • @breadsteeth2562
    @breadsteeth2562 ปีที่แล้ว

    Love from China. Clear explanation and it helps me a lot. Thank you!

  • @faox7565
    @faox7565 6 ปีที่แล้ว

    what a clean teaching you are the best

  • @SaifUlIslam-di5xv
    @SaifUlIslam-di5xv 3 ปีที่แล้ว

    It's a treat watching this as an introduction to what A* is. :D

  • @shreengul6488
    @shreengul6488 5 ปีที่แล้ว

    Great job sir!!! You explain things very clearly and unambiguously . No need to watch any other vedio after watching this.

  • @piotrptak5507
    @piotrptak5507 6 ปีที่แล้ว

    Truly the best explanation of this algorithm we can find

  • @Z3366N
    @Z3366N 5 ปีที่แล้ว

    Thank you for sharing 😊 it was really helpful for me.

  • @zijunliu7765
    @zijunliu7765 5 ปีที่แล้ว

    You explained way better than my professor! Thank you! Now I finally understand it.

  • @Mousta_alpha94
    @Mousta_alpha94 5 ปีที่แล้ว

    thanks Mr john levine your explanation is excellnt

  • @nandudara3845
    @nandudara3845 4 ปีที่แล้ว

    This is a perfect video for understanding A* algorithm

  • @siddarvind6410
    @siddarvind6410 9 หลายเดือนก่อน

    A godsend. This is saving me in my CS Discrete Math class, thank you so much!

  • @saiprasad8311
    @saiprasad8311 5 ปีที่แล้ว

    Good example. Makes it so easy to understand admissibility issue.

  • @mohammadvasegh1754
    @mohammadvasegh1754 4 ปีที่แล้ว +4

    in our country, today is teacher's day good sir. thank you for all of your clarification and examples that you've solved and happy teacher's day to you

    • @johnlevine2909
      @johnlevine2909  4 ปีที่แล้ว +1

      Thank you Mohamad! I'm really glad you find the videos useful.

  • @willardmakinishi6980
    @willardmakinishi6980 3 ปีที่แล้ว +2

    Thank you so much Mr. Levin. Trust me these things did not make any sense in the first encounter with my Lecturer with due respect to him. I have just watched the first minute and i Have decided to download the tutorial. Hopefully I will find your explanations on all the search Algorithms. God bless you and I hope to understand these things before June for my exams

  • @jamesthuo8763
    @jamesthuo8763 5 ปีที่แล้ว +8

    Your videos are the best. Please do Greedy and other topics

  • @harpreetset
    @harpreetset 7 ปีที่แล้ว +1

    really insightful. I am learning AI and have been reading about agent searches for a while. This one is quite helpful. Can you also cover big O notations for time and space for these algorithms? it will help in analyzing in what environments it makes sense to apply them.

    • @johnlevine2909
      @johnlevine2909  7 ปีที่แล้ว +10

      Thanks. I'm planning to do a video comparing the algorithms, including the time and space requirements, in due course.

  • @robs939
    @robs939 2 ปีที่แล้ว

    John the Goat! Thanks man!

  • @koibathekingofgames8522
    @koibathekingofgames8522 ปีที่แล้ว

    The best exemplification that I found until now, It`s worth watching.

  • @PierLim
    @PierLim 6 ปีที่แล้ว

    Thank you for this, it is extremely clear.

  • @zhenyufan8988
    @zhenyufan8988 5 ปีที่แล้ว

    It's a great illustration!! But can u give us a example of how to decide the estimate value from certain node to a goal node?

  • @aditisharma8398
    @aditisharma8398 5 ปีที่แล้ว

    Sir you are the best!

  • @thinhnguyen3163
    @thinhnguyen3163 4 ปีที่แล้ว

    Thank your work, i'm prepairing for AI test next week. Luckily I found this

  • @NinaHProductions1
    @NinaHProductions1 6 ปีที่แล้ว +129

    You are the best teacher and provide the cleanest of explanations - at 5:53 the A* score for A is 17 (5 + 3 +2 + 7) instead of 20 I think?

    • @que_93
      @que_93 5 ปีที่แล้ว +13

      It should be 17, not 20.

    • @ngusumakofu1
      @ngusumakofu1 5 ปีที่แล้ว +4

      Indeed it should be 17

    • @JackyShaw
      @JackyShaw 5 ปีที่แล้ว +2

      I agree too.

    • @know_how5661
      @know_how5661 5 ปีที่แล้ว +2

      yup... its 17

    • @sussananukem7101
      @sussananukem7101 4 ปีที่แล้ว +2

      Nope... He's correct.
      He readded the path cost from A to B since we are revisiting A.
      That is: 5+3+(3)+2+7 =20

  • @AnsumanMohanty
    @AnsumanMohanty 6 ปีที่แล้ว

    Clear and concise. But could you share any resource as to why the heuristic should underestimate the cost ?

  • @sibusisondimande5209
    @sibusisondimande5209 6 ปีที่แล้ว

    Thanxxxx John. You're the best !!!!!

  • @OzDavid
    @OzDavid 6 ปีที่แล้ว

    Amazing explanation. thanks sir

  • @bars5762
    @bars5762 2 ปีที่แล้ว +1

    I'm not very good in English but your explaination is very easy to listen and understand. Thank you very much!

  • @rishabhsharma5645
    @rishabhsharma5645 5 ปีที่แล้ว

    Bravo! Awesome video

  • @maximilianozavala8943
    @maximilianozavala8943 2 ปีที่แล้ว

    Amazing explanation, thank you so much!

  • @baldbadger7644
    @baldbadger7644 3 ปีที่แล้ว

    the lecture was dilivered in a logical and clear manner, thank you so much

  • @alibrahim4686
    @alibrahim4686 6 ปีที่แล้ว

    You are fantastic. Please make more videos.

  • @VaibhavSharma44
    @VaibhavSharma44 6 ปีที่แล้ว

    Thank you so much. Tutorials like these are hard to find :)

  • @CARELESSuwu
    @CARELESSuwu 6 ปีที่แล้ว

    Brilliant!! Thank you sooo much! :)

  • @tonderaimakumborenga2648
    @tonderaimakumborenga2648 6 ปีที่แล้ว

    Simply the best

  • @muhammadhabib3442
    @muhammadhabib3442 7 ปีที่แล้ว +11

    Great Tutorial, Please also Make another tutorial on the Optimality proof of A∗

    • @johnlevine2909
      @johnlevine2909  7 ปีที่แล้ว +2

      Many thanks, and thanks for the suggestion - I think that's a great idea.

  • @dushanrathnayake5007
    @dushanrathnayake5007 2 ปีที่แล้ว +4

    Just brilliant! Thank you so much! At 5:53 the A* score for A is 17 (5 + 3 +2 + 7) instead of 20 I think.

  • @rashidafoodcornervlog654
    @rashidafoodcornervlog654 3 ปีที่แล้ว

    Brilliant man you should make more videos

  • @ramiyousif8024
    @ramiyousif8024 ปีที่แล้ว

    Best video for Heuristic algorithm!! Thank you !!

  • @Imhotep1278
    @Imhotep1278 6 ปีที่แล้ว

    very nice explanation and example, indeed

  • @justafreak15able
    @justafreak15able 6 ปีที่แล้ว

    wawo you explained it very simply and quickly.

  • @uchungnguyen1474
    @uchungnguyen1474 6 ปีที่แล้ว

    sir hat off for your cleaning teaching!

  • @grass666
    @grass666 ปีที่แล้ว

    this tutorial is sooo slay thank you king

  • @dapengzhang4473
    @dapengzhang4473 5 ปีที่แล้ว

    Really like your video, it is really helpful!!!! Thank you!

  • @MuhammadUsman-ry6tp
    @MuhammadUsman-ry6tp 4 ปีที่แล้ว

    One of the best teacher i ever seen

  • @iwayanbagus2271
    @iwayanbagus2271 5 ปีที่แล้ว

    thank you for your videos! I learnt alot

  • @rithikseth1404
    @rithikseth1404 3 ปีที่แล้ว +1

    Perfect A* score for the teacher

  • @hermosillaignacio
    @hermosillaignacio 6 ปีที่แล้ว

    Awesome video, thank you!

  • @maxharris6926
    @maxharris6926 3 ปีที่แล้ว

    Great Video, thank you for explaining A*. For clarification if you find a node that has been visited, but the current path's A* score is less than the cost in the visited set, would you continue on the path and update the A* score in the visited set?

  • @muinmohammadmozammel281
    @muinmohammadmozammel281 4 ปีที่แล้ว

    Short and to the point explanation. Thanks.

  • @message59
    @message59 2 ปีที่แล้ว

    on point 👍🏻 super explanation thank you :)

  • @denvermoodley8487
    @denvermoodley8487 6 ปีที่แล้ว

    Extremely helpful , thank you

  • @ngusumakofu1
    @ngusumakofu1 5 ปีที่แล้ว +1

    Thank you sir. Made it so much clearer

  • @tanvirkaisar7245
    @tanvirkaisar7245 7 หลายเดือนก่อน

    If at some point you get a node having better A* score and the node was already visited (but has inferior A* score than the most recent one), do you replace the old visited node with the current new one?

  • @emrec.4005
    @emrec.4005 5 ปีที่แล้ว

    Well, that marvelous.

  • @thugonomicsstark7238
    @thugonomicsstark7238 3 ปีที่แล้ว +1

    Dear Professor, this is such an amazing video, your way of explaining is just perfect, however i am doing a path planning for the navigation of a mobile robot in the environment, is A* the best technique to do that ? also, can you link me the litterature for this please ?

  • @tiagosousa5278
    @tiagosousa5278 3 ปีที่แล้ว

    holy astar guacamole! perfect explanation!!

  • @MrOkFine
    @MrOkFine 2 ปีที่แล้ว

    Dr. Levine,
    Your teaching is amazing; thank you very much for sharing the knowledge, but can you plesae state some references for students who wants to learn more about such subjects?

  • @kyawnyeinphyo5639
    @kyawnyeinphyo5639 3 ปีที่แล้ว

    Sir, thank you for your amazing explanation

  • @firatyildiz66
    @firatyildiz66 4 ปีที่แล้ว

    Thank you for the clear explanation sir!

  • @ksrikanth1353
    @ksrikanth1353 6 ปีที่แล้ว

    really useful tutorial sir gonna subscribe your channel pls do more videos on ai....

  • @aykutyucel7700
    @aykutyucel7700 6 ปีที่แล้ว

    Thanks a lot! You really make it looks easier!

    • @johnlevine2909
      @johnlevine2909  6 ปีที่แล้ว +1

      Great - glad you found it useful.

  • @samsunny2362
    @samsunny2362 6 ปีที่แล้ว

    Thank you sir for this clear explanation of A* search.

  • @mobeenahmad4711
    @mobeenahmad4711 6 ปีที่แล้ว

    thank you sir it was so clear and concise plz make more tutorials.

  • @MyFingerIsCold
    @MyFingerIsCold 6 ปีที่แล้ว

    Great teacher

  • @LSparkzwz
    @LSparkzwz 5 ปีที่แล้ว

    Very clear and professional, thank you for the lesson

    • @toppoint360
      @toppoint360 5 ปีที่แล้ว

      iLikeKFC can you help me please

  • @raiyan22
    @raiyan22 ปีที่แล้ว

    thank you! Superb!!

  • @hw5622
    @hw5622 6 ปีที่แล้ว

    Good videos! Helped me a a lot, thanks!

  • @adeelali8417
    @adeelali8417 2 ปีที่แล้ว

    Where do you get the initial node heuristics from or do you estimate them?

  • @paulshi2821
    @paulshi2821 3 ปีที่แล้ว

    Thank you for explaining this!