feat(提交列表): 题号填错一道时顶上提示「没有这道题」；← → 也能翻上一条下一条

- 列表接口回带查不到的题号（公开列表只认公开题，比赛列表只认本场的题），
  一次填好几道时打错的那道原来被悄悄忽略
- 方向键恢复成四个都能翻（9 月加的时候就是这样，老师已经用惯了）

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/api/src/routes/flowchart.ts

@@ -25,6 +25,7 @@ import { problemSetJoinTimes } from "../services/problemset"
 import { consumeToken } from "../services/throttling"
 import { buildWordFrequencies } from "../services/word-frequency"
 import { dayStart } from "../time"
+import { unknownDisplayIds } from "./submission-statistics"
 import {
   isAdminRole,
   matchedUsers,
@@ -278,7 +279,7 @@ flowchartRoutes.get("/flowcharts", requireAuth, async (c) => {
   // submission_list_show_all 时非管理员看不到列表。流程图这边一直漏了这道门，
   // 学生把语言切成「流程图」、用户名随便填一个字就能翻出全班的 AI 评分。
   if (!(await getBooleanOption("submission_list_show_all", true)) && !isAdminRole(user)) {
-    return success(c, { results: [], total: 0 } satisfies FlowchartList)
+    return success(c, { results: [], total: 0, unknownProblems: [] } satisfies FlowchartList)
   }
   // 「只看自己」盖过用户名；普通学生不填用户名时也只看自己
   const className = c.req.query("className")?.trim()
@@ -300,7 +301,7 @@ flowchartRoutes.get("/flowcharts", requireAuth, async (c) => {
   if (["S", "A", "B", "C"].includes(grade ?? ""))
     filters.push(eq(schema.flowchartSubmission.aiGrade, grade!))
   const where = and(...filters)
-  const [totalRows, rows] = await Promise.all([
+  const [totalRows, rows, unknownProblems] = await Promise.all([
     // 筛条件已经全落在 flowchart_submission 自己的列上，count 不挂任何 join
     db.select({ value: count() }).from(schema.flowchartSubmission).where(where),
     db
@@ -312,6 +313,7 @@ flowchartRoutes.get("/flowcharts", requireAuth, async (c) => {
       .orderBy(desc(schema.flowchartSubmission.createTime))
       .limit(limit)
       .offset(offset),
+    displayId ? unknownDisplayIds(displayId, null) : [],
   ])
   const joinTimes = await joinTimesFor(
     user,
@@ -337,6 +339,7 @@ flowchartRoutes.get("/flowcharts", requireAuth, async (c) => {
         }) satisfies FlowchartListItem,
     ),
     total: totalRows[0]?.value ?? 0,
+    unknownProblems,
   } satisfies FlowchartList)
 })
 

apps/api/src/routes/submission-statistics.ts

@@ -236,6 +236,31 @@ export async function classNameFilter(className: string) {
  * 和公开题撞号是常态），而公开提交从不指向比赛题（快照核过，0 条）。
  * 查无此题时留恒假条件，少推一个 filter 就成了「不筛」。
  */
+/**
+ * 题号框里查不到的那几个（范围同 problemFilter：公开列表只认公开题，比赛列表只认本场的题）。
+ * 列表把它们回给前端，打错一个字的时候老师能看到提示
+ */
+export async function unknownDisplayIds(displayId: string, contestId: number | null) {
+  const ids = parseDisplayIds(displayId)
+  if (!ids.length) return []
+  const rows = await db
+    .select({ displayId: schema.problem.displayId })
+    .from(schema.problem)
+    .where(
+      and(
+        inArray(
+          sql`lower(${schema.problem.displayId})`,
+          ids.map((id) => id.toLowerCase()),
+        ),
+        contestId === null
+          ? isNull(schema.problem.contestId)
+          : eq(schema.problem.contestId, contestId),
+      ),
+    )
+  const found = new Set(rows.map((row) => row.displayId.toLowerCase()))
+  return ids.filter((id) => !found.has(id.toLowerCase()))
+}
+
 export async function problemFilter(displayId: string, contestId: number | null) {
   // 一次可以筛几道（「这节课」那颗按钮一带就是五道），分隔符和统计面板同一套
   const lowered = parseDisplayIds(displayId).map((id) => id.toLowerCase())

apps/api/src/routes/submission.ts

@@ -37,6 +37,7 @@ import {
   exactUsernameFilter,
   problemFilter,
   submissionStatisticsRoutes,
+  unknownDisplayIds,
   usernameFilter,
 } from "./submission-statistics"
 
@@ -511,7 +512,7 @@ submissionRoutes.get("/submissions", optionalAuth, async (c) => {
   // 「非管理员即受限」，不能写成「是普通用户才受限」——
   // 后者对匿名用户（user 为 null）会短路，匿名反而能看到全部提交，权限大于登录学生。
   if (!(await getBooleanOption("submission_list_show_all", true)) && !isAdminRole(user)) {
-    return success(c, { results: [], total: 0 } satisfies SubmissionList)
+    return success(c, { results: [], total: 0, unknownProblems: [] } satisfies SubmissionList)
   }
   const displayId = c.req.query("problemDisplayId")?.trim()
   const myself = c.req.query("myself") === "1" ? user : null
@@ -542,10 +543,11 @@ submissionRoutes.get("/submissions", optionalAuth, async (c) => {
   const where = and(...filters)
   // count 不 join problem：无条件 join 会让计划器把 count 退化成 seq scan
   // （生产快照实测 7.5ms → 78ms）。题号已经解析成 problem_id，也用不着 join。
-  const [totalRows, rows] = await Promise.all([
+  const [totalRows, rows, unknownProblems] = await Promise.all([
     db.select({ value: count() }).from(schema.submission).where(where),
     // 班级和用户名一样是「圈一小撮人」，走同一条圈选路（见 paginateSubmissionRows）
     paginateSubmissionRows(where, limit, offset, Boolean(username || className)),
+    displayId ? unknownDisplayIds(displayId, null) : [],
   ])
   // 闸门只对学生自己的提交生效，所以只拿这一页里属于他自己的题目去查，一页一次查询
   const [joinTimes, problemsetTitles] = await Promise.all([
@@ -587,6 +589,7 @@ submissionRoutes.get("/submissions", optionalAuth, async (c) => {
         }) satisfies SubmissionListItem,
     ),
     total: totalRows[0]?.value ?? 0,
+    unknownProblems,
   } satisfies SubmissionList)
 })
 
@@ -618,7 +621,7 @@ submissionRoutes.get(
     const where = and(...filters)
     // 一场比赛最多一两千条提交，按 contest_create_time_idx 定位之后怎么滤都不贵，
     // 所以不像公开列表那样分游标 / 圈选两条路
-    const [totalRows, rows] = await Promise.all([
+    const [totalRows, rows, unknownProblems] = await Promise.all([
       db.select({ value: count() }).from(schema.submission).where(where),
       db
         .select(submissionListColumns)
@@ -629,6 +632,7 @@ submissionRoutes.get(
         .orderBy(desc(schema.submission.createTime))
         .limit(limit)
         .offset(offset),
+      displayId ? unknownDisplayIds(displayId, contest.id) : [],
     ])
     // 这里不挂题单防作弊闸门（对比公开列表）：题单里的题必定是非比赛题——加题时卡了
     // `isNull(problem.contestId)`（admin/problemset.ts:232）——而这条列表只出比赛提交，
@@ -656,6 +660,7 @@ submissionRoutes.get(
           }) satisfies SubmissionListItem,
       ),
       total: totalRows[0]?.value ?? 0,
+      unknownProblems,
     } satisfies SubmissionList)
   },
 )