<p>Given a string <code>s</code>, find <em>the longest palindromic <strong>subsequence</strong>&#39;s length in</em> <code>s</code>.</p>

<p>A <strong>subsequence</strong> is a sequence that can be derived from another sequence by deleting some or no elements without changing the order of the remaining elements.</p>

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

<pre>
<strong>Input:</strong> s = &quot;bbbab&quot;
<strong>Output:</strong> 4
<strong>Explanation:</strong> One possible longest palindromic subsequence is &quot;bbbb&quot;.
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;cbbd&quot;
<strong>Output:</strong> 2
<strong>Explanation:</strong> One possible longest palindromic subsequence is &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> consists only of lowercase English letters.</li>
</ul>

class Solution {
public:
    #define ll long long
    int longestPalindromeSubseq(string s) {
        ll n=s.size();
        if(n==1)return 1;
        if(n==2){
            return (s[0]==s[1])?2:1;
        }
        ll ans = 1;
       ll dp[n][n];
        for(ll i=0;i<n;i++){
            dp[i][i]=1;
            if(i<n-1){
                dp[i][i+1] = (s[i]==s[i+1])?2:1;
                ans = max(ans,dp[i][i+1]);
            }
        }
        for(ll l=3;l<=n;l++){
            for(ll i=0;i+l-1<n;i++){
                dp[i][i+l-1] = max(dp[i][i+l-2],dp[i+1][i+l-1]);
                if(s[i]==s[i+l-1]){
                    dp[i][i+l-1] = max(dp[i][i+l-1],dp[i+1][i+l-2]+2);
                }
                ans = max(ans,dp[i][i+l-1]);
            }
        }
        return ans;
    }
};
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