# Is Segment Tree Advanced Data Structure?

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Angela Bailey

Segment Tree is an advanced data structure that is widely used in computer science and programming. It is particularly useful in solving problems related to range queries and updates efficiently. In this article, we will explore the concept of Segment Tree and understand why it is considered an advanced data structure.

## The Basics of Segment Tree

Segment Tree is a binary tree-based data structure that divides a given array into multiple segments or intervals. Each node of the tree represents an interval, and the root node represents the entire array. The leaves of the tree represent individual elements of the array.

One of the key features of Segment Tree is its ability to efficiently handle range queries. A range query involves finding some information or performing an operation on a specific range or interval within the given array. For example, finding the sum, maximum, minimum, or average value within a given range.

### Construction of Segment Tree

The construction of a Segment Tree involves dividing the array recursively into smaller segments until each segment contains only one element. At each step, the parent node stores some information derived from its child nodes, such as the sum of child nodes’ values.

Here’s a step-by-step process for constructing a Segment Tree:

1. Create an empty segment tree with all nodes initialized to zero or some other neutral value.
2. If there is only one element in the array, assign its value to the corresponding leaf node in the segment tree.
3. If there are more than one element in the array:
• Divide the input array into two equal halves.
• Recurse on each half to construct their respective segment trees.
• Merge/Combine the results obtained from the two child nodes to update the parent node.

### Range Query using Segment Tree

Segment Tree allows us to perform range queries efficiently. To perform a range query, we start from the root node and traverse down the tree based on the given range of indices. We can make use of three cases while traversing:

1. If the current segment completely overlaps with the given range, return the information stored in the current node.
2. If the current segment is completely outside the given range, return some neutral value (e.g., zero) or an appropriate value based on the operation being performed.
3. If none of the above cases apply, divide the current segment into smaller segments and recursively query both left and right child nodes.