Count distinct elements in every window

vector <int> countDistinct (int arr[], int n, int k)
{
    int i, count;
	unordered_map<int, int> hash;
	vector<int> c;
	for (int i = 0; i < n - k + 1; i++) {
		hash.clear();
		count = 1;
		hash[arr[i]] = 1;
		for (int j = i; j < i + k; j++) {
			if (hash[arr[j]] != 1) {
				hash[arr[j]] = 1;
				count++;
			}
		}
		c.push_back(count);
	}
	return c;
}