986. Interval List Intersections

We calculate the intersection and merge them as is.

class Solution:
    def intervalIntersection(self, firstList: List[List[int]], secondList: List[List[int]]) -> List[List[int]]:
        intersection = []
        i = 0
        j = 0
        while i < len(firstList) and j < len(secondList):
            [s1, e1], [s2, e2] = firstList[i], secondList[j]
            low = max(s1, s2)
            high = min(e1, e2)    
            if low <= high:
                intersection.append([low, high])
            if e1 < e2:
                i += 1
            else:
                j += 1
        return intersection