Sock Merchant Solution in Java

static int sockMerchant(int n, int[] ar) {
    Set set = new HashSet<Integer>();
    int noOfPairs = 0;
    for (int i=0; i<n; i++) {
        if (set.contains(ar[i])) {
            noOfPairs++;
            set.remove(ar[i]);
        } else {
            set.add(ar[i]);
        }
    }
    return noOfPairs;
}