65 lines
1.7 KiB
Java
65 lines
1.7 KiB
Java
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//给你一个字符串 s ，找出其中最长的回文子序列，并返回该序列的长度。
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//
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// 子序列定义为：不改变剩余字符顺序的情况下，删除某些字符或者不删除任何字符形成的一个序列。
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//
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//
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//
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// 示例 1：
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//
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//
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//输入：s = "bbbab"
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//输出：4
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//解释：一个可能的最长回文子序列为 "bbbb" 。
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//
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//
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// 示例 2：
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//
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//
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//输入：s = "cbbd"
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//输出：2
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//解释：一个可能的最长回文子序列为 "bb" 。
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//
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//
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//
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//
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// 提示：
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//
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//
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// 1 <= s.length <= 1000
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// s 仅由小写英文字母组成
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//
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// Related Topics 字符串 动态规划
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// 👍 508 👎 0
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package leetcode.editor.cn;
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//516:最长回文子序列
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class LongestPalindromicSubsequence {
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public static void main(String[] args) {
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//测试代码
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Solution solution = new LongestPalindromicSubsequence().new Solution();
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System.out.println(solution.longestPalindromeSubseq("bbbab"));
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}
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//力扣代码
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//leetcode submit region begin(Prohibit modification and deletion)
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class Solution {
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public int longestPalindromeSubseq(String s) {
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int length = s.length();
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int[][] dp = new int[length][length];
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for (int i = length - 1; i >= 0; i--) {
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dp[i][i] = 1;
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for (int j = i + 1; j < length; j++) {
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if (s.charAt(i) == s.charAt(j)) {
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dp[i][j] = dp[i + 1][j - 1] + 2;
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} else {
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dp[i][j] = Math.max(dp[i + 1][j], dp[i][j - 1]);
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}
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}
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}
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return dp[0][length - 1];
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}
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}
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//leetcode submit region end(Prohibit modification and deletion)
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}
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