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