<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) {
        if(s.size() == 0) {
            return "";
        }
        int ls = 0;
        vector<int> res;
        for(int i = 0; i < s.size(); i ++) {
            vector<int> ind1 = find_palin(i, i, s);
            vector<int> ind2 = find_palin(i, i+1, s);
            int l1 = ind1[1] - ind1[0] +1;
            int l2 = ind2[1] - ind2[0] +1;
            if(l1 < l2) {
                if(l2 >= ls) {
                    ls = l2;
                    res = ind2;
                }
            } else {
                if(l1 >= ls) {
                    ls = l1;
                    res = ind1;
                }
            }
        }
        return s.substr(res[0], res[1] - res[0]+1);
    }
    
vector<int> find_palin(int ind1, int ind2, string s) {
    if(ind2 >= s.size()) {
        return {ind1, ind1};
    }
    while(ind1 >=0 and ind2 < s.size() and s[ind1] == s[ind2]) {
        ind1--;
        ind2++;
    }
    return {ind1+1, ind2-1};
}
    
    
};
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