<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) {
        int totalSum = 0;
        for(int num : nums) {
            totalSum += num;
        }
        if(totalSum % 2 == 1) {
            return false;
        }
        int target = totalSum / 2;

        unordered_set<int> sumSets;
        sumSets.insert(0);
        for(int i = 0; i < nums.size(); ++i) {
            unordered_set<int> newSet = sumSets;
            for(int sums : sumSets) {
                newSet.insert(sums+nums[i]);
            }
            if(newSet.count(target)) {
                return true;
            }
            sumSets = newSet;
        }
        return false;
    }
};
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