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
use std::collections::HashSet;

impl Solution {
    pub fn count_complete_subarrays(nums: Vec<i32>) -> i32 {
        let mut s = HashSet::new();
        for &x in &nums {
            s.insert(x);
        }
        let cnt = s.len();
        let n = nums.len();
        let mut ans = 0;

        for i in 0..n {
            s.clear();
            for j in i..n {
                s.insert(nums[j]);
                if s.len() == cnt {
                    ans += 1;
                }
            }
        }

        ans
    }
}
