Solution: Interval List Intersections

Explore an optimized approach to solve the interval list intersections problem by iterating through two sorted lists simultaneously. Learn how to identify overlapping intervals efficiently with a two-pointer technique, minimizing time complexity to O(n + m). Understand the logic, implementation, and key steps to implement this solution in Python.

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Statement
Solution
- Naive approach
- Optimized approach using intervals

Statement

Given two lists of closed intervalsA closed interval [start, end] (with start <= end) includes all real numbers x such that start <= x <= end., interval_list_a and interval_list_b, return the intersection of the two interval lists.

Each interval in the lists has its own start and end time and is represented as [start, end]. Specifically:

interval_list_a[i] = [start_i, end_i]
interval_list_b[j] = [start_j, end_j]

The intersection of two closed intervals i and j is either:

An empty set, if they do not overlap, or
A closed interval [max(start_i, start_j), min(end_i, end_j)] if they do overlap.

Also, each list of intervals is pairwise disjoint and in sorted order.

Constraints:

$0 \leq$ interval_list_a.length, interval_list_b.length $\leq 1000$
interval_list_a.length $+$ interval_list_b.length ...