Output in
Const t = MinOverlapTimeRatio;
var player set ; ; ;
Begin
 for each do
  for each relation do
   for each player do
     ←CalculateOverlapTime ( , );
    if QuickSort ( ) > t then
      Select ( ); //select player
        as core-player
    end if
   end for
  end for
 end for
end.
Algorithm 1: Find the core relation group.