<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 mx = *max_element(nums.begin(), nums.end());
        vector<pair<int,int>> arr(mx+1 , {1,1});
        for(int i=2;i<=mx;i++){
            for(int j=1;j*i<=mx;j++){
                arr[i*j].first++;
                arr[i*j].second += i;
            }
        }
        // for(int i=2;i<=mx;i++){
        //     cout<<i<<" "<<arr[i].first<<" "<<arr[i].second<<endl;
        // }
        int ans = 0;
        for(int i=0;i<nums.size();i++){
            if(arr[nums[i]].first == 4)
                ans += arr[nums[i]].second;
        }

        return ans;
    }
};
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