Segment tree meaning in DSA

A segment tree is a data structure used to effectively query and update ranges of array members. It’s typically implemented as a binary tree, with each node representing a segment or range of array elements.

Segment tree

Characteristics of Segment Tree:

• A segment tree is a binary tree with a leaf node for each element in the array.
• Each internal node represents a segment or a range of elements in the array.
• The root node represents the entire array.
• Each node stores information about the segment it represents, such as the sum or minimum of the elements in the segment.

Types of Segment tree:

Based on the type of information stored in the nodes, the tree can be divided into the following few types:

1. Sum segment tree: It stores the sum of elements in each segment of the array and is used in a problem where efficient answer queries are needed about the sum of elements.
2. Min/Max segment tree: It basically stores the minimum or maximum element in each segment of the array.
3. Range update segment tree / Lazy Tree: It allows you to update a range of array elements with a given value. It is used to efficiently update a range of array elements.

Applications of Segment Tree:

• In finding the sum or minimum or maximum of a range of elements in an array.
• In finding the number of elements in a range that satisfy a certain condition, such as being greater than a certain value.
• It can be used in several problems of computational geometry.

To learn more about applications of segment tree, refer to this article.

Advantages of Segment Tree:

• It allows efficient querying and updating of ranges of elements in an array.
• It can help in solving a wide range of problems that involve a range of queries or updates.
• It has a time complexity of O(logN) for both query and update operations where N is the number of nodes in the tree.

To learn more about advantages of segment tree, refer to this article.

Disadvantages of Segment Tree:

• It requires additional memory to store the tree structure and information about the segments
• It may not be the most optimal solution for certain problems.

To learn more about the disadvantages of segment tree, refer to this article.

What else can you read?

• Segment tree | Efficient implementation
• Segment Tree | Sum of given range
• Segment Tree | Range Minimum Query