<p>Given an integer array <code>nums</code>, return <em>the sum of divisors of the integers in that array that have exactly four divisors</em>. If there is no such integer in the array, return <code>0</code>.</p>

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

<pre>
<strong>Input:</strong> nums = [21,4,7]
<strong>Output:</strong> 32
<strong>Explanation:</strong> 
21 has 4 divisors: 1, 3, 7, 21
4 has 3 divisors: 1, 2, 4
7 has 2 divisors: 1, 7
The answer is the sum of divisors of 21 only.
</pre>

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

<pre>
<strong>Input:</strong> nums = [21,21]
<strong>Output:</strong> 64
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,2,3,4,5]
<strong>Output:</strong> 0
</pre>

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

<ul>
	<li><code>1 &lt;= nums.length &lt;= 10<sup>4</sup></code></li>
	<li><code>1 &lt;= nums[i] &lt;= 10<sup>5</sup></code></li>
</ul>

class Solution {
public:
    int sumOfFourDiv(int n) {
        int s = 0, count = 0;
        for (int i = 1; i * i <= n; ++i) {
            if (n % i == 0) {
                if (i == n / i) {
                    s += i;
                    count++;
                } 
                else {
                    count += 2;
                    s += i + n / i;
                }
            }
        }
        if (count == 4) {
            return s;
        } 
        return -1 ; 
    }

    int sumFourDivisors(vector<int>& nums) {
        int s = 0, temp;
        for (auto i = nums.begin(); i != nums.end(); ++i) {
            temp = sumOfFourDiv(*i);
            if (temp != -1) {
                s += temp;
            }
        }
        return s;
    }
};
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