516. Longest Palindromic Subsequence

https://leetcode.com/problems/longest-palindromic-subsequence/description/
    int longestPalindromeSubseq(string s) {
        int n = s.size();
        vector<vector<int>> dp(n, vector<int> (n, 0));
        for(int j=0; j<n; j++) {
            dp[j][j] = 1;
            for(int i=j-1; i>=0; i--) {
                if(s[i] == s[j]) dp[i][j] = dp[i+1][j-1] + 2;
                else dp[i][j] = max(dp[i+1][j], dp[i][j-1]);
            }
        }
        return dp[0][n-1];
    }