// FILE: DoubleMin.cpp
// FIND THE INDEX OF THE SMALLEST VALUE IN A FLOATING POINT SUBARRAY
// CONSISTING OF ELEMENTS x[start_index] THROUGH x[end_index]

int find_index_of_min
   (const apvector <double>& x,	// IN: array of elements
    int start_index,			// IN: subscript of first element
    int end_index)				// IN: subscript of last element

// Returns the subscript of the smallest element in the subarray.
// Returns -1 if the subarray bounds are invalid.
// Pre:  The subarray is defined and 0 <= start_index <= end_index.
// Post: x[min_index] is the smallest value in the array.

{
   // Local data ...
   int min_index;			// index of the smallest element found
   int i;				// index of the current element

   // Validate subarray bounds
   if ((start_index < 0) || (start_index > end_index))
   {
      cerr << "Error in subarray bounds" << endl;
      return -1;			// return error indicator
   }

   // Assume the first element of subarray is smallest and check the rest.
   // min_index will contain subscript of smallest examined so far.

   min_index = start_index;
      for (i = start_index + 1; i <= end_index; i++)
         if (x[i] < x[min_index])
            min_index = i;

   // All elements are examined and min_index is
   // the index of the smallest element.
   return min_index;		// return result for valid subarray
} // end find_index_of_min