LCA – Lowest Common Ancestor

Tutorial on LCA algorithm. We use Binary Lifting to get O(N*log(N)) preprocessing and O(log(N)) to find the lowest common ancestor of two nodes in a tree.
Two homework problems:
2) Given a tree with weighted edges (i.e. every edge has some value), answer queries "given two nodes U and V, find minimum weight along path U-V". (I don't have a source for this one).

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[Errichto]

Here are two homework problems for you:
2) Given a tree with weighted edges (i.e. every edge has some value), answer queries "given two nodes U and V, find minimum weight along path U-V". (I don't have a source for this one).

[allwell]

Generally, it is difficult to learn from extra-ordinary people like you. But you are exception to that also. Thank you so much.

[beastfromeast-wd]

After watching numerous errichto videos, whenever I explain my code to anyone else I get errichto's accent.
Your videos are awesome.

[ksg]

I am simple man, i see Errichto is teaching something i will click it

[coefficient]

Errichto should be in the UN protected list ❤.

[sonugupta]

The analogy with binary search was a great hint what we are going to do here. Thanks Errichto

[ShubhamKumar-mexy]

It's a great initiative by you to teach algorithms. Looking forward for more such great videos. Also add some more practice problems of whatever you explain.

[hydroUNI]

YES! A THOUSAND TIMES YES! Thank you much for making a video on LCA!

[alexandruhritcan]

I know how to do LCA with RMQ, but this solution is something else
I love it to bits 💚💚

[glaucoa.]

Errichto one of the best, I love his videos.

[desyfer]

This guy doing a god's work...whoever is the god of cp

[RajatSingh-dgov]

I know that these problems are very easy for you but trust me these are very hard for me.
And if you are making it, I will watch it!. You are literal GOD in coding!.
Please keep on making these very basic videos on concepts, I really liked your Binary Search video as well!.
Thanks

[saitejaballa]

The way you explained the binary lifting is just awesome ❤❤

[bethsuni]

Thanks for the lectures. I like this format a lot: short videos with explanation, code, and example.

[iPaperPlane]

Can't believe this still *F R E E*

[prathamkumar]

The preprocessing of vector<vector<int> up will take O(Nlog(N)) time so how this solution TC is O(logN)

[itz_me_imraan]

His voice and explanation both are soothing🙂

[saiprasadduduka]

Some of your videos(like this one) are so well made. Thnx🔥

[josephwong]

awesome explanation of LCA and Binary Lifting

[simone]

Thank you i was searching for this after the binary lifting video 👍