new_contents: # Time:  O(n)
  # Space: O(h)
  
  # You are given a data structure of employee information,
  # which includes the employee's unique id, his importance value and his direct subordinates' id.
  #
  # For example, employee 1 is the leader of employee 2, and employee 2 is the leader of employee 3.
  # They have importance value 15, 10 and 5, respectively.
  # Then employee 1 has a data structure like [1, 15, [2]], and employee 2 has [2, 10, [3]],
  # and employee 3 has [3, 5, []]. Note that although employee 3 is also a subordinate of employee 1,
  # the relationship is not direct.
  #
  # Now given the employee information of a company,
  # and an employee id, you need to return the total importance value of this employee and all his subordinates.
  #
  # Example 1:
  # Input: [[1, 5, [2, 3]], [2, 3, []], [3, 3, []]], 1
  # Output: 11
  #
  # Explanation:
  # Employee 1 has importance value 5, and he has two direct subordinates:
  # employee 2 and employee 3. They both have importance value 3.
  # So the total importance value of employee 1 is 5 + 3 + 3 = 11.
  #
  # Note:
  # One employee has at most one direct leader and may have several subordinates.
  # The maximum number of employees won't exceed 2000.
  
  """
  # Employee info
  class Employee(object):
      def __init__(self, id, importance, subordinates):
          # It's the unique id of each node.
          # unique id of this employee
          self.id = id
          # the importance value of this employee
          self.importance = importance
          # the id of direct subordinates
          self.subordinates = subordinates
  """
  class Solution(object):
      def getImportance(self, employees, id):
          """
          :type employees: Employee
          :type id: int
          :rtype: int
          """
          if employees[id-1] is None:
              return 0
          result = employees[id-1].importance
          for id in employees[id-1].subordinates:
              result += self.getImportance(employees, id)
          return result
  
  
  # Time:  O(n)
  # Space: O(w), w is the max number of nodes in the levels of the tree
  class Solution2(object):
      def getImportance(self, employees, id):
          """
          :type employees: Employee
          :type id: int
          :rtype: int
          """
          result, q = 0, collections.deque([id])
          while q:
              curr = q.popleft()
              employee = employees[curr-1]
              result += employee.importance;
              for id in employee.subordinates:
                  q.append(id)
          return result
  
subject: Create employee-importance.py