<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 len = s.length();
        string ans = "";
        ans+=s[0];
        int i, j;
        for(int k=0;k<len;k++){
            i = k;
            j = k;
            // cout<<s[i]<<" "<<s[j]<<endl;;
            while(i>-1 && j<len && s[i]==s[j]){
                // cout<<s.substr(i, j-i+1)<<endl;
                if(ans.length()<s.substr(i, j-i+1).length()){
                    ans = s.substr(i, j-i+1);
                }
                i--;
                j++;
            }
            i = k;
            j = k+1;
            while(i>-1 && j<len && s[i]==s[j]){
                // cout<<s.substr(i, j-i+1)<<endl;
                if(ans.length()<s.substr(i, j-i+1).length()){
                    ans = s.substr(i, j-i+1);
                }
                i--;
                j++;
            }
            
        }
        return ans;
    }
};
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