public class Main {public static void main(String[] args) {Scanner sc = new Scanner(System.in);String s=sc.next();int n=s.length();long res=0;boolean[][] f=new boolean[n][n];for(int i=0;i<n;i++) Arrays.fill(f[i],true);for(int i=n-1;i>=0;i--){for(int j=i+1;j<n;j++){f[i][j]=(s.charAt(i)==s.charAt(j)&amp;&amp;f[i+1][j-1]);if(f[i][j]) res++;}}System.out.print(res);}}这样写为啥只能过25%呢,我以为要去个重结果去重完只能过15%了