AP计算机教程11-7：简单多选题

What would the following code return from mystery([90, -30, 50], 50)?

public static int mystery(int[] elements, int target)
{
  for (int j = 0; j < elements.length; j++)
  {
      if (elements[j] == target)
      {
         return j;
      }
  }
  return -1;
}

What would the following code return from mystery([90, -30, 50], -20)?

 public static int mystery(int[] elements, int target)
 {
   for (int j = 0; j < elements.length; j++)
   {
      if (elements[j] == target)
      {
         return j;
      }
  }
  return -1;
}

Consider the binarySearch method below. How many times would the while loop execute if you first do int[] arr = {2, 10, 23, 31, 55, 86} and then call binarySearch(arr,2)?

public static int binarySearch(int[] elements, int target) {
   int left = 0;
   int right = elements.length - 1;
   while (left <= right)
   {
      int middle = (left + right) / 2;
      if (target < elements[middle])
      {
         right = middle - 1;
      }
      else if (target > elements[middle])
      {
         left = middle + 1;
      }
      else {
         return middle;
      }
    }
    return -1;
}

Which sort contains a recursive call?

Under what condition will an ascending insertion sort execute the slowest?