最长回文子串

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);             

        while(scanner.hasNextLine()){ 
            String s=scanner.nextLine();
       System.out.println(longestPalindrome(s));
    }
}
 public static int longestPalindrome(String s) {
     int n=s.length();
     boolean[][] pal=new boolean[n][n];
     //pal[i][j] 表示s[i...j]是否是回文串
     int maxLen=0;
     for (int i=0;i<n;i++){  // i作为终点
         int j=i;    //j作为起点
         while (j>=0){
             if (s.charAt(j)==s.charAt(i)&&(i-j<2||pal[j+1][i-1])){
                 pal[j][i]=true;
                maxLen=Math.max(maxLen, i-j+1);
             }
             j--;
         }
     }
     return maxLen;
    }
}

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