n元树中的搜索算法

Question

I am trying to implement search algorithm for n-ary tree. Following is the code that I have written:

public class Employee
{

    public int EmployeeId { get; set; }
    public string Level { get; set; }
    public int BillCode { get; set; }

    public virtual List<Employee> ReportsTo { get; set; }
}

I need to do BFS on the tree to find the element in the child nodes and to stop the recursion when the element is found in the tree. The code that I wrote so far is:

static bool ClosestManager(Employee a, Employee b) //a contains all the tree elements and b is the one that I need to find
    {
      if (a.EmployeeId == b.EmployeeId)
            return true;
        if (a.ReportsTo != null)
        {
            foreach (var curremployee in a.ReportsTo)
            {
                ClosestManager(curremployee, b);
            }
        }
        return false;
    }

This one always returns false even if the element exists in the subtree. It is because of the return false in the end. If I remove it than I get a compiler error saying that all code path must return a value.

How do I stop recursion once the element is found in the tree ?

Answer 1

Just return true if a ClosestManager is found in the recursive call:

static bool ClosestManager(Employee a, Employee b) //a contains all the tree elements and b is the one that I need to find
{
  if (a.EmployeeId == b.EmployeeId)
    return true;
  if (a.ReportsTo != null)
  {
    foreach (var curremployee in a.ReportsTo)
    {
      if (ClosestManager(curremployee, b))
         return true;
    }
  }
  return false;

}