title: Java recursion sum
body: <p>I need a class Person to describe persons. Each person has a name and an array consisting of Person-objects, which represent the person's children. The person class has a method getNumberOfDescendants, which returns an integer equal to the total number of descendants of the person, i.e. his children plus grandchildren plus their children etc. Is there a simple way to do this using recursion?</p>
  
  <p>What if you want to count the descendants in a certain generation only? In other words, getNumberOfDescendants(int generation) would return the number of children if generation=1, number of grandchildren if generation=2 etc.</p>