Strassen’s Matrix Multiplication | Divide and Conquer | GeeksforGeeks

Find Complete Code at GeeksforGeeks Article: www.geeksforgeeks.org/strassen...
This video is contributed by Harshit Verma
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[@nebras__]

thank you .. my left ear loved the video

[@brianevans4]

Your headphones are on the wrong way. It should be your right ear

[@chengyaozheng8536]

@@brianevans4 Doesn't matter, it flows out from the other ear anyways.

[@ashujha9165]

BRO THIS VIDEO'S AUDIO IS LIKE 3D AUDIO.

[@siddhvyas6330]

hahahaha

[@ayushiojha6376]

Right😂

[@soumitramehrotra2045]

where is the addition of matrices comes into the picture as you say ut takes O(N^2) for addition?

[@nazishschughtai5712]

amazing video.. thanks

[@arushiraj8607]

thanks😊, very helpful.

[@manojprajapati932]

Strassen’s Matrix Multiplication looks incorrect. The correct algorithm is here en.wikipedia.org/wiki/Strassen_algorithm

[@saifhaider2310]

what if matrix is oddxodd i.e if 7x7
then how to devide into 4 matrix

[@erick9016]

you convert them into 8x8 by adding a row & column of just zeroes. Everything else works identically

[@googol-boy-data]

It's necessary, because Strassen algorithm can only be done on 2^n x 2^n matrix

[@shivatejachavali787]

@@googol-boy-data nice

[@keshavmaheshwari521]

why is it not preferred for practical purposes

[@Nellak2011]

Turns out, the optimal amount of operations in the optimal algorithm would perform only 4 operations instead of Strassen's 7.
Because, the optimal algorithm would run in O(n^2) time

[@bonbonpony]

What lead you to this conclusion?
Just because the resulting matrix has 4 cells, doesn't mean that this is the minimal number of multiplications required, because you still need some way to combine 8 cells coming from 2 factor matrices somehow. And they are combined as dot products. The only thing you can do is to reshape their formulas in such a way that would lower the number of multiplications (at the cost of increasing the number of additions - those are usually less expensive to calculate), by reusing some partial results.

[@solsane5217]

If you could implement a sequential O(n^2) matrix multiplication algo you'd get a Nobel prize.

[@muskanrai2282]

Good job 👍 sir

[@ankitvashisht7350]

why strassen's method is not preferred for practical purposes ?

[@anshul4249]

Most probably because we would prefer small calculations several times rather than large calculations.....

[@vishalkumarsingh5509]

Because it only works for square matrixes

[@KeshaShah1106]

how do u come up with p1 to p7 formula?

[@harshitv]

That is Strassen's formula. All you can do is memorise it. See here: www.geeksforgeeks.org/easy-way-remember-strassens-matrix-equation/

[@frozenarmymc2182]

It’s just an invention, some found it and it worked

[@cvismenu]

Thank you

[@satyam_krishna]

not useful,just reading the ppt

[@chiefjudge8456]

You didn't explain the method. You also wrote lg7 (or log_2 7) as log 7 which is confusing.

[@shushrutgupta]

If your ever read Introduction to Algorithms by Cormen, you will notice that, log_2(n) is written as lg n and log_e(n) is written as ln n

[@DeepakKumar-wv7jg]

Rtaaaa maarrr

[@khorshidvahidi]

In computer science, any log is assumed to have base 2 unless specified otherwise

[@brianevans4]

I think generally speaking log(n) is assumed to be log base 10 of n

[@bonbonpony]

@@brianevans4 Unfortunately, it depends on the country/school/book. Different authors use different notations (as if there wasn't enough confusion already :q ).

[@asoahmadzade4305]

nice job

[@sanjayjeyavel9871]

It would have been even more useful if u had explained the implementation of the algo!!! nice video though!

[@cahitskttaramal3152]

This was a bad explanation. I mean why bother if you won't go deep and explain the theory behind it in the video? I found this whole info and understand in 20 seconds on google before watch this. No need to watch 4.5 mins video for this. Man I hate to dislike informative videos on CZcams but sometimes they really push!

[@bonbonpony]

As they say, for every Wikipedia page, there's an Indian video on CZcams trying to tell you the same with pseudo-English.

[@kartikanand6348]

@@bonbonpony I mean, I'm an Indian, but lol, that's to the point XD

[@poojapoojadhapte1430]

Matrix multiplication algorithm

[@DeepakKumar-wv7jg]

Saaale ka bol rha hai khud ki pta hau

[@shashankvashishtha4454]

could not understand

[@drwhackadoodle360]

This isn't explained properly at all

[@bonbonpony]

You should have expected that from the beginning after hearing Indian accent, shouldn't you? :q

[@ronakpatil6081]

@@bonbonpony so ,instead watch abdul bari another indian with great explanation of the algorithm
it would help you definitely then you will not have any problem with indian accent😂

[@bonbonpony]

@@ronakpatil6081 I don't have a problem with Indian accent. (In fact, I watched quite a lot of Indian video lectures from NPTEL etc.). I have a problem with Indian people who think that they understand something and they can teach about it, and then flooding CZcams with crappy videos recorded with a cucumber, with traffic noises in the background, and "explaining" to me with their poor unintelligible English the stuff that I could just read from Wikipedia. Or worse, making videos in Hindi but putting English titles to deceive English-speaking people into watching them.

[@kemal4282]

can u guys stop speaking like hindi while speaking english

[@Nikhil-pm6rn]

can you guys stop speaking in english

[@shivatejachavali787]

sad reacts only

[@vishnuramj4660]

@@Nikhil-pm6rn hindi theriyadhu poda

[@Nikhil-pm6rn]

@@vishnuramj4660 OK bro, I will start a channel just for you and tamilians.

[@bonbonpony]

@@Nikhil-pm6rn There should be an entire separate CZcams for them, so that they didn't have to spam the regular CZcams with their crappy unintelligible videos about every single subject on Earth.

[@rishabhraj865]

have you ever hear about Abdul Bari, go get some skill how to teach..