Interview Question for Search Engineer, Front End at LinkedIn:

just run the random funtion and replace elements.

To perform perfect randomization of an array of elements there is a well known method (all n! permutations of the array are equally probable assuming a perfect random number generator)

public static void randomize(int[] a) {
    int tmp, index;
    for (int i = 0; i < a.length; i++){
      index = (int) (Math.random() * (a.length - i)) + i;
      tmp= a[i];
      a[i] = a[index];
      a[index] = tmp;
    }
 }