class Solution {
public int longestPalindromeSubseq(String s) {
if (s == null || s.length() < 1) return 0;
int len = s.length();
int[][] dp = new int[len][len];
for (int i = len - 1; i >= 0 ;i--) {
dp[i][i] = 1;
for (int j = i + 1; j < len; j++) {
if (s.charAt(i) == s.charAt(j)) {
dp[i][j] = dp[i + 1][ j - 1] + 2;
} else {
dp[i][j] = Math.max(dp[i + 1][j], dp[i][j - 1]);
}
}
}
return dp[0][len - 1];
}
}
class Solution {
public int longestPalindromeSubseq(String s) {
if (s == null || s.length() < 1) return 0;
int len = s.length();
int[][] dp = new int[len][len];
for (int i = len - 1; i >= 0 ;i--) {
for (int j = i; j < len; j++) {
if (s.charAt(i) == s.charAt(j)) {
if ( j - i >= 2) {
dp[i][j] = dp[i + 1][ j - 1] + 2;
} else {
dp[i][j] = j - i + 1;
}
} else {
if (j - i >= 2) {
dp[i][j] = Math.max(dp[i + 1][j], dp[i][j - 1]);
} else {
dp[i][j] = 1;
}
}
}
}
return dp[0][len - 1];
}
}