986. Interval List Intersections

Python

Time Exceed Try

class Solution:
    def intervalIntersection(self, firstList: List[List[int]], secondList: List[List[int]]) -> List[List[int]]:
        if not firstList or not secondList:
            return []

        results = []
        result = []

        uppbound = max(firstList[-1][1], secondList[-1][1])+1
        lowerbound = min(firstList[0][0], secondList[0][0])
        first_current = None
        second_current = None

        for num in range(lowerbound, uppbound):
            if not first_current or num > first_current[1]:
                if firstList:
                    first_current = firstList.pop(0)
                if result:
                    results.append(result)
                    result = []

            if not second_current or num > second_current[1]:
                if secondList:
                    second_current = secondList.pop(0)
                if result:
                    results.append(result)
                    result = []

            first_enabled = (num >= first_current[0] and num <= first_current[1])
            second_enabled = (num >= second_current[0] and num <= second_current[1])

            if first_enabled and second_enabled:
                if not result:
                    result = [num, num]
                else:
                    result[1] = num

            if (not first_enabled or not second_enabled) and result:
                results.append(result)
                result = []


        if result:
            results.append(result)

        return results