protected Map<Integer,List<Solution>> createGridMap(){
  AdaptiveGridArchive archive=getArchive();
  Map<Integer,List<Solution>> result=new HashMap<Integer,List<Solution>>();
  for (  Solution solution : archive) {
    int index=archive.findIndex(solution);
    List<Solution> solutions=result.get(index);
    if (solutions == null) {
      solutions=new ArrayList<Solution>();
      result.put(index,solutions);
    }
    solutions.add(solution);
  }
  return result;
}

protected Map < Integer , List < Solution > > createGridMap ( ) { AdaptiveGridArchive archive = getArchive ( ) ; Map < Integer , List < Solution > > result = new HashMap < Integer , List < Solution > > ( ) ; for ( Solution solution : archive ) { int index = archive . findIndex ( solution ) ; List < Solution > solutions = result . get ( index ) ; if ( solutions == null ) { solutions = new ArrayList < Solution > ( ) ; result . put ( index , solutions ) ; } solutions . add ( solution ) ; } return result ; }
returns a mapping from grid index to the solutions occupying that grid index . the key is the grid index , and the value is the list of solutions occupying that index .
