class Solution:
    def carFleet(self, target: int, position: List[int], speed: List[int]) -> int:
        #TC: O(n log n)
        #SC: O(n)
        #n =len(position)
        #Just consider the time to target of each car

        if len(position) == 0:
            return 0

        car = []
        for i in range(len(position)):
            car.append((position[i], (target - position[i]) / speed[i]))
        car.sort(reverse = True)

        res = 1
        pivot = car[0][1]
        for i in range(1, len(position)):
            if car[i][1] <= pivot:
                continue
            else:
                pivot = car[i][1]
                res += 1
        return res