fix: 类型修复

Author: CodeJudge

frontend/src/pages/Problems.tsx

@@ -72,6 +72,7 @@ export default function Problems() {
   const { user } = useAuth();
   const [userStats, setUserStats] = useState<{ accepted: number } | null>(null);
   const totalProblems = stats?.total ?? 0;
+  const totalPages = data ? Math.ceil(data.total / pageSize) : 0;
 
   // Keyboard pagination
   useEffect(() => {
@@ -205,8 +206,6 @@ export default function Problems() {
     }
   };
 
-  const totalPages = data ? Math.ceil(data.total / pageSize) : 0;
-
   const getPageNumbers = (): (number | '...')[] => {
     if (totalPages <= 7) {
       return Array.from({ length: totalPages }, (_, i) => i + 1);