/**

* Determines whether the given array is a permutation.

* A permutation is defined to be an int array that

* contains each number from 0 through n - 1 exactly

* once, where n is the length of the array. In other

* words, each value is between 0 and n - 1, inclusive,

* and there are no duplicates.

* @param arr

* given array

* @return

* true if the given array is a permutation, false otherwise

*/

public static boolean isPermutation(int[] arr)

{

return null;

}