Merge overlapping intervals
Given closed intervals [start,end] with start <= end, merge all overlaps including shared endpoints. Return intervals sorted by start. Inputs are valid JSON and must not be modified unless the algorithm uses a local copy. This exercise probes typed data modeling, boundary handling, and algorithm selection.
Input
One JSON value: number[][]. See the sample for its exact shape.
Output
One compact JSON value of type number[][]. Strings include JSON quotes; arrays preserve the specified order.
Constraints
Array/string lengths are 0 to 10000 unless stated otherwise. Numbers are integers in [-1000000,1000000]; all computed results fit the safe integer range.
Example
Input
[[1,3],[2,6],[8,10]]
Output
[[1,6],[8,10]]
Example 2 input
[[1,9],[2,3],[1,9]]
Output
[[1,9]]
Checks a boundary or contrasting case beyond the public examples.
Public test cases (2)
Input
[[1,3],[2,6],[8,10]]
Expected output
[[1,6],[8,10]]
Input
[]
Expected output
[]
Hints (2)
- Start with the required output order and the empty-input behavior.
- Sort by start and extend the last merged interval
Target complexity: time O(n log n) · space O(n)