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Distance Between Nodes in A Tree
By jhjfbsbfkbjfnfnfjfj, history, 7 years ago, In English

In a weighted tree, how to find for some node (u) the distance to another node (v) (answering Q queries effeiciently)? Constraints N <=10^3, Queries <=10^3

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7 years ago, hide # |
 
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Since N is small you can apply BFS starting from u in each query and print the distance of node v which will take O(n) time for each query. An efficient way to answer each query in O(logn) is using LCA which can be found in O(logn) using binary lifting.

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7 years ago, hide # |
 
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I teach all these concepts with practice problems , here is the graph theory playlist where you can find this concept along with other concepts. https://www.youtube.com/playlist?list=PL2q4fbVm1Ik64I3VqbVGRfl_OgYzvzt9m hope this helps.

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