Selection Sort

template < class ForwardIterator >
void g_selection_sort (ForwardIterator beg, ForwardIterator end)
{
  ForwardIterator i, j, k;
  for (i = beg; i != end; ++i)
  {
    k = i;
    for (j = i; j != end; ++j)
      if (*j < *k)
        k = j;
    Swap (*i, *k);
  }
}

• in place
• not stable (call to Swap may change order of equal elements)
• exactly n(n + 1)/2 calls to comparison operator on any input
• run time = Θ(n²) (worst, average, best cases)
• requires forward iterators