I got a similar question for my phone interview. The difference is that the duplicated number is allowed. So, think that is a follow-up of this question.

How do you modify your code to allow duplicated number?

```
public class RandomizedSet {
ArrayList<Integer> nums;
HashMap<Integer, Integer> locs;
java.util.Random rand = new java.util.Random();
/** Initialize your data structure here. */
public RandomizedSet() {
nums = new ArrayList<Integer>();
locs = new HashMap<Integer, Integer>();
}
/** Inserts a value to the set. Returns true if the set did not already contain the specified element. */
public boolean insert(int val) {
boolean contain = locs.containsKey(val);
if ( contain ) return false;
locs.put( val, nums.size());
nums.add(val);
return true;
}
/** Removes a value from the set. Returns true if the set contained the specified element. */
public boolean remove(int val) {
boolean contain = locs.containsKey(val);
if ( ! contain ) return false;
int loc = locs.get(val);
if (loc < nums.size() - 1 ) { // not the last one than swap the last one with this val
int lastone = nums.get(nums.size() - 1 );
nums.set( loc , lastone );
locs.put(lastone, loc);
}
locs.remove(val);
nums.remove(nums.size() - 1);
return true;
}
/** Get a random element from the set. */
public int getRandom() {
return nums.get( rand.nextInt(nums.size()) );
}
}
```