<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 {
public:
    string longestPalindrome(string &s) {

        int start=-1,end=-1;

        int n=s.length();
        int len=0;
        for(int i=0;i<n;++i){
            for(int j=n-1;j>=0;--j){
                if(s[i]==s[j] && len<(j-i+1)){
                    int k=1;
                    while(j-k>i+k && s[i+k]==s[j-k]){
                        k++;
                    }

                    if(j-k<=i+k && len<j-i+1){
                        start=i;end=j;
                        len=j-i+1;
                    }
                }

            }
        }

        return s.substr(start,len);

    }
};
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