What is a Segment Tree?

A Segment Tree is a versatile tree-based data structure that allows for efficient querying of range-based problems, such as finding the sum, minimum, or maximum of a subarray. It excels at problems requiring both range queries and point updates.

What is the time complexity of Segment Tree operations?

Building a segment tree takes O(n) time. Both range queries and updates on a segment tree have a time complexity of O(log n), where n is the number of elements in the original array.

Advanced Data Structures

Segment Tree Interview Questions

Efficiently solve range query problems by mastering the Segment Tree. This guide covers implementation, common interview questions, and provides AI-powered feedback.

Segment Tree for Range Sum

A Segment Tree is a binary tree used for storing information about intervals or segments. Each node in the segment tree represents an interval. It allows for faster querying of range-based problems.

                            class SegmentTree {
                            constructor(arr) {
                            this.n = arr.length;
                            this.tree = new Array(4 * this.n);
                            this.build(arr, 0, 0, this.n - 1);
                            }
                            
                            build(arr, node, start, end) {
                            if (start === end) {
                            this.tree[node] = arr[start];
                            return;
                            }
                            let mid = Math.floor((start + end) / 2);
                            this.build(arr, 2 * node + 1, start, mid);
                            this.build(arr, 2 * node + 2, mid + 1, end);
                            this.tree[node] = this.tree[2 * node + 1] + this.tree[2 * node + 2];
                            }
                            
                            query(l, r) { /* ... implementation ... */ }
                            update(idx, val) { /* ... implementation ... */ }
                            }
                        

AI Coach Hint: The size of the segment tree array is typically 4n to be safe, where n is the size of the input array. This accounts for the worst-case height of the tree. The core idea is divide and conquer, breaking down the array into segments represented by tree nodes.