Problem:

Find number of Employees Under every Employee
Given a dictionary that contains mapping of employee and his manager as a number of (employee, manager) pairs like below.

For example:
{ “A”, “C” },
{ “B”, “C” },
{ “C”, “F” },
{ “D”, “E” },
{ “E”, “F” },
{ “F”, “F” }

In this example C is manager of A, C is also manager of B, F is manager of C and so on.

Write a function to get no of employees under each manager in the hierarchy not just their direct reports. It may be assumed that an employee directly reports to only one manager. In the above dictionary the root node/ceo is listed as reporting to himself.

Output should be a Dictionary that contains following.

A – 0
B – 0
C – 2
D – 0
E – 1
F – 5

Solution:

– Easy to build topological graph for each employee and count
– Either use hash for this

Latest Source Code:
Github: EmployeesManager.java

Output:

 Result: {A=0, B=0, C=2, D=0, E=1, F=5}