How should I practice Subtract One Half-Open Interval from Another?

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Subtract One Half-Open Interval from Another

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Problem statement

You are given two finite floating-point intervals intervalA and intervalB. Each array contains exactly [start, end] and represents the half-open interval [start, end).

Return the portions of intervalA that are not covered by intervalB.

If the intervals do not overlap, return intervalA.
If intervalB completely covers intervalA, return an empty matrix.
Otherwise, return each non-empty residual interval from left to right.
Intervals that only touch at an endpoint do not overlap. Never return an empty interval such as [x, x).

Function

subtractInterval(intervalA: double[], intervalB: double[]) → double[][]

Examples

Example 1

intervalA = [2.5,7.5]intervalB = [4.3,9.3]return = [[2.5,4.3]]

The overlap is [4.3, 7.5), so the only part of intervalA left uncovered is [2.5, 4.3).

Example 2

intervalA = [1.0,10.0]intervalB = [3.0,7.0]return = [[1.0,3.0],[7.0,10.0]]

intervalB lies strictly inside intervalA, leaving one residual interval on each side. They are returned from left to right.

Example 3

intervalA = [1.0,3.0]intervalB = [3.0,5.0]return = [[1.0,3.0]]

The intervals only touch at endpoint 3.0. Because they are half-open, they do not overlap, so intervalA remains unchanged.

Example 4

intervalA = [2.0,6.0]intervalB = [0.0,10.0]return = []

intervalB covers every point in intervalA, so no residual interval remains.

Constraints

intervalA.length == 2 and intervalB.length == 2.
Every endpoint is a finite double value.
intervalA[0] < intervalA[1].
intervalB[0] < intervalB[1].