HJ85 最长回文子串

1. 题目

HJ85 最长回文子串

读题

 

 

考查点

 

2. 解法

思路

 

代码逻辑

 

具体实现

public class HJ085 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println(longestParaline(sc.nextLine()));
    }

    public static int longestParaline(String str) {
        int n = str.length();
        boolean[][] dp = new boolean[n][n];
        int maxlen = 1;
        for (int len = 1; len <= n; len++) {
            for (int i = 0; i < n - len + 1; i++) {
                int j = i + len - 1;
                if (len == 1) {
                    dp[i][j] = true;
                } else if (len == 2) {
                    dp[i][j] = str.charAt(i) == str.charAt(j);
                } else {
                    dp[i][j] = dp[i + 1][j - 1] && str.charAt(i) == str.charAt(j);
                }
                if (dp[i][j] && len > maxlen) {
                    maxlen = len;
                }
            }

        }

        return maxlen;
    }
}

 

3. 总结