class Solution {
public int longestPalindromeSubseq(String s) {
int[][] dp = new int[s.length()][s.length()];
//base
for(int i = 0;i<s.length();i++){
dp[i][i] = 1;
}
for(int i = 1;i<s.length();i++){
for(int j = 0;j<i;j++){
dp[i][j] = 0;
}
}
//状态转移
for(int i = s.length()-1 ;i>=0;i--){
for(int j =i+1;j<s.length();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][s.length()-1];
}
}
