leetcode: finished #516

content/leetcode/2023/8.md

@@ -3,6 +3,37 @@ title: "2023.8"
 draft: false
 ---
 
+# 2023.8.31
+
+```python
+#
+# @lc app=leetcode.cn id=516 lang=python3
+#
+# [516] 最长回文子序列
+#
+
+# @lc code=start
+class Solution:
+    def longestPalindromeSubseq(self, s: str) -> int:
+        if not s:
+            return 0
+        n = len(s)
+        dp = [[0]*n for _ in range(n)]
+        for i in range(n):
+            dp[i][i] = 1
+        for i in range(n-2, -1, -1):
+            for j in range(i+1, n):
+                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]
+# @lc code=end
+```
+
 # 2023.8.30
 
 ```python