1var assert = require('assert');
2
3function longestPalindromeSubseq(s) {
4    if (!s) {
5        return 0;
6    }
7    let grid = Array(s.length).fill('').map(() => Array(s.length).fill(0));
8    for (let i = s.length - 1; i >= 0; i--) {
9        grid[i][i] = 1;
10        for (let j = i + 1; j < s.length; j++) {
11            if (s[i] == s[j]) {
12                grid[i][j] = grid[i + 1][j - 1] + 2;
13            } else {
14                grid[i][j] = Math.max(grid[i + 1][j], grid[i][j - 1]);
15            }
16        }
17    }
18    return grid[0][s.length - 1];
19}
20
21try {
22    assert.deepEqual(longestPalindromeSubseq('bbbab'), 4);
23    console.log('PASSED: ' + "`longestPalindromeSubseq('bbbab')` should return `4`");
24} catch (err) {
25    console.log(err);
26}
27
28try {
29    assert.deepEqual(longestPalindromeSubseq('cbbd'), 2);
30    console.log('PASSED: ' + "`longestPalindromeSubseq('cbbd')` should return `2`");
31} catch (err) {
32    console.log(err);
33}
34
35try {
36    assert.deepEqual(longestPalindromeSubseq('abbcdabbc'), 5);
37    console.log('PASSED: ' + "`longestPalindromeSubseq('abbcdabbc')` should return `5`");
38} catch (err) {
39    console.log(err);
40}