It was hard to find the exact code for this. As I’ve found it, I am sharing it

This concept is used mainly when the problem involves subtree queries.

Suppose, we are given a tree and are asked to find sum of all the nodes of a subtree under node-‘x’.

And we are also given some point updates.

We can represent the tree as an array.

We do this by doing the Euler tour of the tree.

For a subtree under node ‘x’,all those elements/nodes lie in a range {l,r} of the array.

Now, we can use the segment tree concept to solve the problem

Problem Link:-https://www.hackerearth.com/problem/algorithm/subtree-queries/

My code link:-

https://www.hackerearth.com/submission/25562623/