Count Complete Subarrays in an Array
<p>You are given an array <code>nums</code> consisting of <strong>positive</strong> integers.</p>

<p>We call a subarray of an array <strong>complete</strong> if the following condition is satisfied:</p>

<ul>
	<li>The number of <strong>distinct</strong> elements in the subarray is equal to the number of distinct elements in the whole array.</li>
</ul>

<p>Return <em>the number of <strong>complete</strong> subarrays</em>.</p>

<p>A <strong>subarray</strong> is a contiguous non-empty part of an array.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,3,1,2,2]
<strong>Output:</strong> 4
<strong>Explanation:</strong> The complete subarrays are the following: [1,3,1,2], [1,3,1,2,2], [3,1,2] and [3,1,2,2].
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [5,5,5,5]
<strong>Output:</strong> 10
<strong>Explanation:</strong> The array consists only of the integer 5, so any subarray is complete. The number of subarrays that we can choose is 10.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 1000</code></li>
	<li><code>1 &lt;= nums[i] &lt;= 2000</code></li>
</ul>
Array; Hash Table; Sliding Window
class Solution {
    public int countCompleteSubarrays(int[] nums) {
        Set<Integer> s = new HashSet<>();
        for (int x : nums) {
            s.add(x);
        }
        int cnt = s.size();
        int ans = 0, n = nums.length;
        for (int i = 0; i < n; ++i) {
            s.clear();
            for (int j = i; j < n; ++j) {
                s.add(nums[j]);
                if (s.size() == cnt) {
                    ++ans;
                }
            }
        }
        return ans;
    }
}