<p>Given an integer array <code>nums</code>, return <code>true</code> <em>if you can partition the array into two subsets such that the sum of the elements in both subsets is equal or </em><code>false</code><em> otherwise</em>.</p>

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

<pre>
<strong>Input:</strong> nums = [1,5,11,5]
<strong>Output:</strong> true
<strong>Explanation:</strong> The array can be partitioned as [1, 5, 5] and [11].
</pre>

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

<pre>
<strong>Input:</strong> nums = [1,2,3,5]
<strong>Output:</strong> false
<strong>Explanation:</strong> The array cannot be partitioned into equal sum subsets.
</pre>

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

<ul>
	<li><code>1 &lt;= nums.length &lt;= 200</code></li>
	<li><code>1 &lt;= nums[i] &lt;= 100</code></li>
</ul>

class Solution {
public:
    bool canPartition(vector<int>& nums) {
        const auto sum = std::accumulate(nums.begin(), nums.end(), 0);
        if (sum & 1U) return false;
        const auto target = sum / 2;
        std::ranges::sort(nums);
        vector<int> curr_sums{nums.front()};
        vector<int> next_sums{};
        vector<int> buffer{};

        for (size_t i = 1; i < nums.size(); ++i) {
            auto x = nums[i];
            if (x == target) {
                return true;
            }
            for (auto y : curr_sums) {
                if (x + y == target) {
                    return true;
                }
                if (x + y < target) {
                    next_sums.push_back(x + y);
                }
            }
            std::ranges::set_union(curr_sums, next_sums, std::back_inserter(buffer));
            curr_sums = std::move(buffer);
            next_sums.clear();
            buffer.clear();
        }
        return false;
    }
};
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