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].

?Exemple1:

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?<= 109

• endi?< starti+1

• 0 <= startj?< endj?<= 109

• endj?< startj+1

Accepted

345,884

Submissions

484,734

比較兩個的開頭最大值lower，跟結尾最小值upper；

lower<uppper

就把lower，upper 放到list中；

然后如果a[i][1]<b[j][1]就i++;

else j++;

最后返回數(shù)組；

Runtime:?3 ms, faster than?90.49%?of?Java?online submissions for?Interval List Intersections.

Memory Usage:?42.9 MB, less than?88.57%?of?Java?online submissions for?Interval List Intersections.