Number of K 's such that the given array can be divided into two sets satisfying the given conditions | Function to return the count of K 's  such that the array can be divided  into two sets containing equal number  of elements when all the elements less  than K are in one set and the rest  of the elements are in the other set ; Sort the given array ; Return number of such Ks ; Driver code
function two_sets ( a , n ) { a . sort ( ) ; return a [ n / 2 ] - a [ ( n / 2 ) - 1 ] ; } var a = [ 1 , 4 , 4 , 6 , 7 , 9 ] ; var n = a . length ; document . write ( two_sets ( a , n ) ) ;