Interval List Intersections

For two arrays of closed intervals given as input, intervalListA and intervalListB, where each interval has its own start and end time, write a function that returns the intersection of the two interval arrays.

Statement

For example, the intersection of [3, 8] and [5, 10] is [5, 8].

Constraints

• 0 ≤ intervalListA.length, intervalListB.length ≤ 1000
• 0 ≤ start[i] < end[i] ≤ 10⁹, where i is used to indicate intervalListA
• end[i] < start[i + 1]
• 0 ≤ start[j] < end[j] ≤ 10⁹, where j is used to indicate intervalListB
• end[j] < start[j + 1]

Examples

Example 1

Input:

• intervalListA = [[1, 4], [5, 8], [9, 12]]
• intervalListB = [[2, 3], [6, 10]]

Explanation:

• [1, 4] ∩ [2, 3] = [2, 3]
• [5, 8] ∩ [6, 10] = [6, 8]
• [9, 12] has no overlap with any interval in intervalListB.

Output: [2, 3], [6, 8]

Example 2

Input:

• intervalListA = [[3, 8], [10, 15]]
• intervalListB = [[5, 10], [12, 20]]

Explanation:

• [3, 8] ∩ [5, 10] = [5, 8]
• [10, 15] ∩ [12, 20] = [12, 15]

Output: [5, 8], [12, 15]