Random Access Example

 template  <typename  RI>
 void  random_shuffle(RI  begin,  RI  end)  {
         if  (begin  ==  end)  return;
         for (RI  i = begin + 1;  i != end;  ++i)  {
                 RI  other  =  begin  +
                                   nrand(i  -  begin  +  1);
                 swap(*i,  *other);
     }
 }