Practice Interval List Intersections

Read the task, work through the examples, and check your approach against the constraints. Use the original LeetCode task for coding and submissions.

Medium#986

LeetCode Problem

Interval List Intersections

Array Two Pointers Line Sweep

Problem Statement

You are given two lists of closed intervals, firstList and secondList, where firstList[i] = [starti, endi] and secondList[j] = [startj, endj]. Each list of intervals is pairwise disjoint and in sorted order. Return the intersection of these two interval lists. A closed interval [a, b] (with a <= b) denotes the set of real numbers x with a <= x <= b. The intersection of two closed intervals is a set of real numbers that are either empty or represented as a closed interval. For example, the intersection of [1, 3] and [2, 4] is [2, 3].

Source: Interval List Intersections on LeetCode. Use the original task for its coding environment and submissions.

Examples

# Example 1

Input

firstList = [[0,2],[5,10],[13,23],[24,25]], secondList = [[1,5],[8,12],[15,24],[25,26]]

Output

[[1,2],[5,5],[8,10],[15,23],[24,24],[25,25]]

# Example 2

Input

firstList = [[1,3],[5,9]], secondList = []

Output

[]

Constraints

0 <= firstList.length, secondList.length <= 1000

firstList.length + secondList.length >= 1

0 <= starti < endi <= 10^9

endi < starti+1

0 <= startj < endj <= 10^9

endj < startj+1

Review your practice with PhantomCodeAI

After trying the problem yourself, use the app to discuss your approach, complexity, and edge cases.

Start Free