Segment Tree Build II
The structure of Segment Tree is a binary tree which each node has two attributes start and end denote an segment / interval.
start and end are both integers, they should be assigned in following rules:
- The root's start and end is given by build method.
- The left child of node A has
end=(A.left + A.right) / 2.
- The right child of node A has
start=(A.left + A.right) / 2 + 1,
- if start equals to end, there will be no children for this node.
Implement a build method with a given array, so that we can create a corresponding segment tree with every node value represent the corresponding interval max value in the array, return the root of this segment tree.
[3,2,1,4]. The segment tree will be:
[0, 3] (max = 4) / \ [0, 1] (max = 3) [2, 3] (max = 4) / \ / \ [0, 0](max = 3) [1, 1](max = 2)[2, 2](max = 1) [3, 3] (max = 4)
Segment Tree (a.k.a Interval Tree) is an advanced data structure which can support queries like:
which of these intervals contain a given point
which of these points are in a given interval