Array Rotation In Place using C++ (Juggling Algorithm)

To Rotate an array by k positions to the left in-place i.e O(1) space complexity by Juggling Algorithm and creating a program/code using C++ to implement the logic of rotating the array by k positions using juggling algorithm.

0:00 What is Array Rotation?
1:08 Array Rotation In-Place Algorithm Explained
4:36 How to find the number of sets?
5:11 Juggling Algorithm using GCD
13:18 C++ Code for Array Rotation In Place

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#arrayrotation #jugglingalgorithm #codewhoop

[indianstate]

This is the best explanation of array rotation using Juggling Algorithm out there. It is better than the video by GeeksForGeeks. Thank you.

[rajatgupta]

Best explanation of juggling algorithm I've ever seen.

[harshitgarg]

What I think the idea/ need of using GCD in this algorithm is that it helps combining 2 cases into single case.
Think of this algo without GCD, then we have 2 scenarios, 1- When both n and k are multiples of each other, in this case we know that we will form n/k number of cycles/set and then move elements in those cycle iteratively (using j+d % n and when d == i then we will increment our outer loop) in this way we will go for each cycle.
2- When n and k are not multiples also think in a way that you want k(th) element on first position and likewise the succeeding elements so we will use the same approach (d+j % n till d == 0) in this case we will encounter d == 0 only one time and hence we know that will be the end of algorithms because before d will end up being 0 it will cover all the possible values.

So now if we see that these 2 conditions 1- when outer loop runs n/k times and 2- when outer loop will run only 1 time. this can be achieved or calculated using gcd(n, k).
So either increase your lines of code making 2 handling 2 different scenarios then you will be clear or if you understand this then apply GCD and make your code short.

[hemendiranbaskaran]

Best explanation of juggling algorithm I've ever seen. And by the way it is way better than the video by GeeksForGeeks. Thank you.

[sarvottampriyadarshee]

bro, I just subscribed watching only this video of yours!
Hats off to your explanations!
don't stop making videos!

[kamleshbhalui]

Best Explanation of this Problem I found on the Internet.Thanks.

[krishnaverma]

Till now i did not come across such a simple
Good job
Good animation
I watched 3 different tutorials but here I understood.
Thanks....

[ravindraverma]

Only video! which explains juggling algo very well.👍

[m.vineeth]

Seriously this is the best video I have seen till now, the way you have explained it was awesome. Thanks a lot for writing the blog as well.
This is a pure gem teaching style 💯

[neerajoberai]

better than any arrays rotation videos available so far i understood it so damn well thnx :)

[QuantenMagier]

Nice work there, but modulo is effectively implemented by division, so with modern branch prediction and condition k<n it would probably be more efficient to do: d=j+k; if(d>=n) d-=n;
But juggling algorithm probably behaves bad on caches anyway as addresses spread over the whole array range; at least for large k this could be a problem.

[adarshvaranasi]

Thanks dude, and explanation is so good🔥

[AkashVerma-ly]

Thanks for the explanation with the help of a beautiful insight.❤

[gamingwithhemend]

The best explanation for juggling algo !!!!

[saikiransripada]

Your explanation is precise, quick and straight to the point.

[IsteyakMahmud]

Best explanation of juggling algorithm.. Thank you.. ♥️♥️♥️

[RitikSharma-pcyj]

Wow...so much clear cut explanation...thanks

[rachitshukla]

Thanks for the concise explanation! Cheers!

[dhairyapasrija]

What's the intuition behind the gcd part?

[vincent]

OMG sir you hit that topics so clearly, big thanks for you, help me a lot