// ----- Example:  Selection Sort -----
//
// This program reads in an array of doubles up to MAX_LENGTH elements
// long and sorts its entries. The elements in the array are then printed 
// in sorted order.
// -----------------------------------------------
#include<iostream>
using namespace std;

const int MAX_LENGTH = 1000;
void select_sort( double[] , int  );
void swap       ( double& , double& );
int indexOfLeast( double[] , int  );


int main()
{
   double a[MAX_LENGTH];                        // Get input.
   int i, n;
   cout << "\n Enter the number of elements to be sorted: ";
   cin  >> n;
   cout << "\n Enter the elements one by one (no commas):  \n\n";
   for (i = 0; i < n; ++i)
   {
       cout << "enter a[" << i << "]:  ";
       cin >> a[i];
   }

   select_sort( a, n );                        // Sort it.

   cout << " \n The sorted array is: \n\n";    // Print output.
   i=0;
   while ( i < n ) 
   {
       cout << a[i] << "  ";
       ++i;
   }
   cout << "\n\n";
   return 0;
}


void select_sort( double a[], int length )
{
   int i, i_min;                       // Recursively swap the first element 
   for ( i = 0; i < length-1; ++i )    // of the unsorted part of a[] with a 
   {                                   // least element of the unsorted part.
     i_min = i + indexOfLeast( a+i, length -i );
     if (i_min > i)                    
        swap ( a[i], a[i_min] );
   }
}


void swap ( double& a, double& b)
{
  double t = a;
         a = b;
         b = t;
}


int indexOfLeast( double a[], int length )
{
   int i, answer = 0; 
   double leastElement = a[0];        // The least element examined so far.
   for (i = 1; i < length; i++ ) 
     if ( a[i] < leastElement )
     {
        leastElement = a[i];
        answer     = i;
     }  
   return answer;
}