static int findSum ( int [ ] arr , int n ) {
  fact [ 0 ] = 1 ;
  for ( int i = 1 ;
  i < n ;
  i ++ ) fact [ i ] = i * fact [ i - 1 ] ;
  int mul = 0 ;
  for ( int i = 0 ;
  i <= n - 1 ;
  i ++ ) mul += ( int ) Math . pow ( 2 , i ) * ncr ( n - 1 , i ) ;
  int ans = 0 ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) ans += mul * arr [ i ] ;
  return ans ;
}

static int findSum ( int [ ] arr , int n ) { fact [ 0 ] = 1 ; for ( int i = 1 ; i < n ; i ++ ) fact [ i ] = i * fact [ i - 1 ] ; int mul = 0 ; for ( int i = 0 ; i <= n - 1 ; i ++ ) mul += ( int ) Math . pow ( 2 , i ) * ncr ( n - 1 , i ) ; int ans = 0 ; for ( int i = 0 ; i < n ; i ++ ) ans += mul * arr [ i ] ; return ans ; }
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