1443. Minimum Time to Collect All Apples in a Tree

https://leetcode.com/problems/minimum-time-to-collect-all-apples-in-a-tree/

from collections import defaultdict
class Solution:
    def minTime(self, n: int, edges: List[List[int]], hasApple: List[bool]) -> int:
        self.d = defaultdict(list)
        for edge in edges:
            f,t = edge
            self.d[f].append(t)
        def dfs(node):
            res = 0
            for child in self.d[node]:
                res += dfs(child)
            
            if node != 0 and (res > 0 or hasApple[node]):
                res+=2
            return res
        return dfs(0)