<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 sumFourDivisors(vector<int>& nums) {

        int sum = 0;
        for(auto &x : nums){
            vector<int>divisors = calcDivisors(x);
            if(divisors.size() == 4){
                sum += accumulate(divisors.begin(),divisors.end(),0);
            }
        }

        return sum;
        
    }



    vector<int> calcDivisors(int x){
        vector<int>divisors;
        divisors.push_back(1);
        divisors.push_back(x);

            for(int i = 2;i*i <= x;i++){

                if(x%i == 0){
                    if((x/i) == i){
                        divisors.push_back(i);
                    }else{
                        divisors.push_back(i);
                        divisors.push_back(x/i);
                    }
                }
            }

            return divisors;
    }
};
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