private static void changeNext(int[] arrnext, int key, int oldnext, int newnext) {
    for (int i = key - 1; i >= 0; i--) {
      if (arrnext[i] == oldnext) {
        arrnext[i] = newnext;
      }
      else {
        break;
      }
    }
  }
private static void changeNext(int[] arrnext, int key, int oldnext, int newnext)