<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>


int solve(string text1, string text2) {
    int i1 = text1.length(), j1 = text2.length();
    vector<int> prev(i1 + j1 + 1, 0), cur(i1 + j1 + 1, 0);
    for (int i = 1; i <= i1; i++) {
        for (int j = 1; j <= j1; j++) {
            if (text1[i - 1] == text2[j - 1])
                cur[j] = 1 + prev[j - 1];
            else
                cur[j] = max(prev[j], cur[j - 1]);
        }
        prev = cur;
    }
    return prev[j1];
}

class Solution {
public:
    int longestPalindromeSubseq(string s) {
        string reverseS = s;
        reverse(s.begin(), s.end());
        return solve(s, reverseS);
    }
};
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