最长回文子串

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import java.util.Scanner;

public class Main {
    public String longestPalindrome(String s) {
        int curLen = 0;
        int start = -1;
        char[] array = s.toCharArray();
        for (int i = 0; i < array.length; i++) {
            if (isPalindrome(array, i - curLen - 1, i)) {
                start = i - curLen - 1;
                curLen += 2;
            } else if (isPalindrome(array, i - curLen, i)) {
                start = i - curLen;
                curLen += 1;
            }
        }
        return new String(array, start, curLen);
    }

    private boolean isPalindrome(char[] array, int start, int end) {
        if (start < 0) {
            return false;
        }
        while (start < end) {
            if (array[start++] != array[end--]) {
                return false;
            }
        }
        return true;
    }

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

参考链接

  1. (AC) relatively short and very clear Java solution
  2. LeetCode 5. Longest Palindromic Substring
  3. 最长回文子串——Manacher 算法