516.longest-palindromic-subsequence_dp.cpp

class Solution {
public:
    int longestPalindromeSubseq(string s) {
        int dp[1001][1001] = {};
        int n = s.size();
        for (int i = n - 1; i >= 0; --i) {
            dp[i][i] = 1;
            for (int j = i + 1; j < n; ++j) {
                dp[i][j] = max(dp[i + 1][j], dp[i][j - 1]);
                if(s[i] == s[j]) {
                    dp[i][j] = 2 + dp[i + 1][j - 1];
                }
            }
        }
        return dp[0][n - 1];
    }
};