public class Solution
extends Object
757 - Set Intersection Size At Least Two\.
Hard
An integer interval `[a, b]` (for integers `a < b`) is a set of all consecutive integers from `a` to `b`, including `a` and `b`.
Find the minimum size of a set S such that for every integer interval A in `intervals`, the intersection of S with A has a size of at least two.
**Example 1:**
**Input:** intervals = \[\[1,3],[1,4],[2,5],[3,5]]
**Output:** 3
**Explanation:**
Consider the set S = {2, 3, 4}. For each interval, there are at least 2 elements from S in the interval.
Also, there isn't a smaller size set that fulfills the above condition.
Thus, we output the size of this set, which is 3.
**Example 2:**
**Input:** intervals = \[\[1,2],[2,3],[2,4],[4,5]]
**Output:** 5
**Explanation:** An example of a minimum sized set is {1, 2, 3, 4, 5}.
**Constraints:**
* `1 <= intervals.length <= 3000`
* `intervals[i].length == 2`
* 0 <= ai < bi <= 108