<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 {
    int ml= -1;
    int mr = -1;
    int mlen = -1;
public:
     void getPalindromFromMiddle(string s, int start, int end)
       {
           if (s == "" ) 
               return;
           int tmpr = start+end;
           int tmpl = start;
           while (tmpl >= 0 && tmpr < s.size() )
           {
            if (s[tmpl] == s[tmpr]){
               if (mlen < tmpr -tmpl +1) {
            mlen = tmpr-tmpl+1;
            mr = tmpr;
            ml= tmpl;
           }
               tmpl--;
               tmpr++;
            } else {
                break;
            }
           }
          // cout << "end" << end << "start" << start << "mlen" << mlen << "ml" << ml << "mr" << mr << endl;
           
       }
    string longestPalindrome(string s) {
      
       int i = 1;
     
       s.insert(s.begin(), '#');
       while (i<s.size())
       {
          // if (size -i < mlen/2)
          //     break;
           getPalindromFromMiddle(s, i,0 );
           getPalindromFromMiddle(s, i,1 );
           
           i++;
       }
       return s.substr(ml, mr - ml +1);
    }
};

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