Aggregate Employee Counts and Overdue Days Over a Group Hierarchy (Tree)

Problem You have a company organization where groups form a tree. Three inputs are provided: group_tree: a dictionary mapping a parent group name to a list of its immediate child group names (parent_group -> [child_group1, child_group2, ...]). employee_group: a dictionary mapping an employee ID to the name of the group they belong to (employee_id -> group_name). employee_overdue: a dictionary mapping an employee ID to their non-negative number of overdue days (employee_id ->…