<p>Given a string <code>s</code>, return <em>the longest</em> <span data-keyword="palindromic-string"><em>palindromic</em></span> <span data-keyword="substring-nonempty"><em>substring</em></span> in <code>s</code>.</p>

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

<pre>
<strong>Input:</strong> s = &quot;babad&quot;
<strong>Output:</strong> &quot;bab&quot;
<strong>Explanation:</strong> &quot;aba&quot; is also a valid answer.
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;cbbd&quot;
<strong>Output:</strong> &quot;bb&quot;
</pre>

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

<ul>
	<li><code>1 &lt;= s.length &lt;= 1000</code></li>
	<li><code>s</code> consist of only digits and English letters.</li>
</ul>

class Solution:
    def longestPalindrome(self, s: str) -> str:
        n = len(s)
        if(n == 1):
            return s[0]

        ls = s[0]
        ls_cnt = 1

        r = [[0]*n for _ in range(n)]
        for i in range(n):
            r[i][i] = 1
        for i in range(1, n):
            for j in range(i):
                if(s[i] == s[j]):
                    if(j == i-1):
                        r[i][j] = 1
                        if(ls_cnt<2):
                            ls_cnt = 2
                            ls = s[j:(i+1)]
                    else:
                        if((r[i-1][j+1]==1)):
                            r[i][j] = 1
                            cnt = i-j+1
                            if(ls_cnt<cnt):
                                ls_cnt = cnt
                                ls = s[j:(i+1)]
        return ls
                    

        
24300