<p>You are given an integer array <code>nums</code>.</p>

<p>You should move each element of <code>nums</code> into one of the two arrays <code>A</code> and <code>B</code> such that <code>A</code> and <code>B</code> are non-empty, and <code>average(A) == average(B)</code>.</p>

<p>Return <code>true</code> if it is possible to achieve that and <code>false</code> otherwise.</p>

<p><strong>Note</strong> that for an array <code>arr</code>, <code>average(arr)</code> is the sum of all the elements of <code>arr</code> over the length of <code>arr</code>.</p>

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

<pre>
<strong>Input:</strong> nums = [1,2,3,4,5,6,7,8]
<strong>Output:</strong> true
<strong>Explanation:</strong> We can split the array into [1,4,5,8] and [2,3,6,7], and both of them have an average of 4.5.
</pre>

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

<pre>
<strong>Input:</strong> nums = [3,1]
<strong>Output:</strong> false
</pre>

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

<ul>
	<li><code>1 &lt;= nums.length &lt;= 30</code></li>
	<li><code>0 &lt;= nums[i] &lt;= 10<sup>4</sup></code></li>
</ul>

struct Helper {
    size_t operator()(const pair<int, int>& P) const {
        return hash<int>()(P.first + 128 * P.second);
    }
};
unordered_set<pair<int, int>, Helper> sums;
class Solution {
public:
    bool splitArraySameAverage(const vector<int>& nums) {
        ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
        sums.clear();
        sums.insert({0, 0});
        unordered_set<pair<int, int>, Helper> targets;
        int n = nums.size(), a = 1, b = n - 1, total = accumulate(nums.begin(), nums.end(), 0);
        while(a <= b){
            if((a * total) % n == 0 && (b * total) % n == 0){
                targets.insert({a, a * total / n});
            }
            a++, b--;
        }
        if(targets.empty()) return false;
        for(const int &i : nums){
            unordered_set<pair<int, int>, Helper> temp;
            for(const pair<int, int>& P : sums){
                if(P.first > 14) continue;
                temp.insert({P.first + 1, P.second + i});
            }
            sums.insert(temp.begin(), temp.end());
            for(const pair<int, int> &target : targets){
                if(sums.find(target) != sums.end()) return true;
            }
        }
        return false;
    }
};
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