Added Python solution for "Time Needed to Inform All Employees"

Author: Kyrylo-Ktl

Python/Time Needed to Inform All Employees.py

@@ -0,0 +1,20 @@
+from collections import defaultdict
+from typing import List
+
+
+class Solution:
+    """
+    Time:   O(n)
+    Memory: O(n)
+    """
+
+    def numOfMinutes(self, n: int, head_id: int, manager: List[int], inform_time: List[int]) -> int:
+        def dfs(boss: int) -> int:
+            return inform_time[boss] + max((dfs(emp) for emp in subordinates[boss]), default=0)
+
+        subordinates = defaultdict(set)
+
+        for u, v in enumerate(manager):
+            subordinates[v].add(u)
+
+        return dfs(head_id)