<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:
    def canPartition(self, nums: List[int]) -> bool:
        def helper(index, left, right):
            if (index, right) in memo:
                return memo[(index, right)]
            if (index, left) in memo:
                return memo[(index, left)]
            if index >= len(nums):
                return left == right
            
            lef = helper(index+1, left+nums[index], right)
            if lef:
                memo[(index, right)] = True
                return True
            rig = helper(index+1, left, right+nums[index])
            if rig:
                memo[(index, right)] = True
                return True
            memo[(index, right)] = False
            return False
        nums.sort()
        memo = {}
        return helper(0, 0, 0)
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