4. Query on a Segment Tree #

Created Saturday 25 July 2020

• Query - O(log N)
• Return the value.

There are 3 cases:

1. Completey outside, i.e need 3,3 have 1,2. No calls further, return 0.
2. Completely inside - e.g 2,4 need 1-5, no calls further, return the answer.
3. Partial - e.g 2,4 need 3-4, return left and right ones:
   1. Left inside - start, mid
   2. Right inside - mid+1, end

return a+b; queryTree.h