#include <iostream>
#include <ctime>
#include <cstdlib>
#include <algorithm>
#include <iterator>
using namespace std ;

void fill_with_unique_rand( int* array, int N, int min_value, int max_value )
{
  int available = max_value - min_value +1 ;
  int required = N ;

  for( int i=0 ; i<available ; ++i )
    if( ( rand() % (available-i) ) < required )  // we have to choose required 
                                 // out of the remaining (available-i)
    {
      --required ;
      array[required] = min_value + i ;
    }

  random_shuffle( array, array+N ) ;   // if needed
}

template< int N > inline void fill_array_with_unique_rand( int (&array)[N], 
                                           int min_value, int max_value )
{ fill_with_unique_rand( array, N, min_value, max_value ) ; }

int main()
{
  srand( unsigned( time(0)) ) ;

  int a[10] ;  fill_array_with_unique_rand( a, 101, 200 ) ;
  copy( a, a+sizeof(a)/sizeof(*a), ostream_iterator<int>(cout," ") ) ; 
  cout << '\n' ;

  int b[20] ;  fill_array_with_unique_rand( b, 20, 40 ) ;
  copy( b, b+sizeof(b)/sizeof(*b), ostream_iterator<int>(cout," ") ) ; 
  cout << '\n' ;
}