1376 Time Needed to Inform All Employees

https://leetcode.com/problems/time-needed-to-inform-all-employees/

solution

class Solution:
    def numOfMinutes(self, n: int, head_id: int, managers: List[int], inform_time: List[int]) -> int:
        def dfs(employee_id: int) -> int:
            max_time = 0
            for subordinate in graph[employee_id]:
                max_time = max(max_time, dfs(subordinate) + inform_time[employee_id])
            return max_time

        graph = collections.defaultdict(list)
        for i, mng_id in enumerate(managers):
            if mng_id != -1:
                graph[mng_id].append(i)

        return dfs(head_id)

时间复杂度：O(n) 空间复杂度：O(n)