You have a data structure of employee information, including the employee's unique ID, performance rating, and direct subordinates' IDs.
You are given an array of employees employees where:
employees[i].id is the ID of the ith employee.
employees[i].rating is the individual rating value of the ith employee. (0-5)
employees[i].subordinates is a list of the IDs of the direct subordinates of the ith employee.
Given an string id that represents an employee's ID, return the rating value of the employee/manager.
The rating of a manager is the average of the ratings of his/her subordinates (both direct & indirect) and his individual rating
E(A)
/
E(B) E(C)
/ \
E(D) E(E)

R(A) = (R(B) + R(C) + R(D) + R(E) + R(A))/5

Input:         
[
{"employeeA", 4, ["employeeB", "employeeC"]}, 
{"employeeB", 3, ["employeeD", "employeeE"]},
{"employeeC", 3, []}, 
{"employeeD", 5, []},
{"employeeE", 4, []}
]