for (int j = 0; j < size; j++)
for (int j = i; j < size; j++)
  protected void clear() {    for (int i = 0; i < size; i++)      for (int j = 0; j < size; j++)	if (chart[i][j] == null)	  chart[i][j] = new HashMap();	else	  chart[i][j].clear();  }