<p>Given a string <code>s</code>, partition <code>s</code> such that every <span data-keyword="substring-nonempty">substring</span> of the partition is a <span data-keyword="palindrome-string"><strong>palindrome</strong></span>. Return <em>all possible palindrome partitioning of </em><code>s</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<pre><strong>Input:</strong> s = "aab"
<strong>Output:</strong> [["a","a","b"],["aa","b"]]
</pre><p><strong class="example">Example 2:</strong></p>
<pre><strong>Input:</strong> s = "a"
<strong>Output:</strong> [["a"]]
</pre>
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= s.length &lt;= 16</code></li>
	<li><code>s</code> contains only lowercase English letters.</li>
</ul>

class Solution:
    def partition(self, s: str) -> List[List[str]]:

        ans=set()
        n=len(s)
        def calculate(i,l):
            if i>=n:
                f=0
                for j in l:
                    if j!=j[::-1]:
                        f=1
                        break
                if f==0:
                    ans.add(tuple(l))
                return
            calculate(i+1,l+[s[i]])
            if l:   
                calculate(i+1,l[:-1]+[l[-1]+s[i]])
        calculate(0,[])
        
            
        return ans
        
        
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