<p>You are given a string <code>s</code>. You can convert <code>s</code> to a <span data-keyword="palindrome-string">palindrome</span> by adding characters in front of it.</p>

<p>Return <em>the shortest palindrome you can find by performing this transformation</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<pre><strong>Input:</strong> s = "aacecaaa"
<strong>Output:</strong> "aaacecaaa"
</pre><p><strong class="example">Example 2:</strong></p>
<pre><strong>Input:</strong> s = "abcd"
<strong>Output:</strong> "dcbabcd"
</pre>
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>0 &lt;= s.length &lt;= 5 * 10<sup>4</sup></code></li>
	<li><code>s</code> consists of lowercase English letters only.</li>
</ul>

class Solution:
    def shortestPalindrome(self, s: str):
        if not s:
            return ""

        akt = [s[0]]
        n = len(s)
        pali = 1

        for i in range(1, n):
            akt.append(s[i])
            polowa = len(akt) // 2

            if len(akt) % 2 == 0:
                rever = akt[polowa:]
                rever.reverse()
                if akt[:polowa] == rever:
                    pali = i + 1
            else:
                rever = akt[polowa+1:]
                rever.reverse()
                if akt[:polowa] == rever:
                    pali = i+1

        kupa = list(s[pali:])
        kupa.reverse()
        wynik = ''.join(kupa) + s

        return wynik
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