diff --git a/account/decorators.py b/account/decorators.py
index c5dec8f..6f3e274 100644
--- a/account/decorators.py
+++ b/account/decorators.py
@@ -127,7 +127,7 @@ def check_contest_permission(check_type="details"):
             return None
 
         if self.contest.contest_type == ContestType.PASSWORD_PROTECTED_CONTEST:
-            if not check_contest_password(request.session.get(CONTEST_PASSWORD_SESSION_KEY, {}).get(self.contest.id), self.contest.password):
+            if not check_contest_password(request.session.get(CONTEST_PASSWORD_SESSION_KEY, {}).get(str(self.contest.id)), self.contest.password):
                 return self.error("Wrong password or password expired")
 
         if self.contest.status == ContestStatus.CONTEST_NOT_START and check_type != "details":
diff --git a/contest/views/oj.py b/contest/views/oj.py
index 2f27978..62a1b88 100644
--- a/contest/views/oj.py
+++ b/contest/views/oj.py
@@ -94,7 +94,7 @@ class ContestPasswordVerifyAPI(AsyncAPIView):
 
         if CONTEST_PASSWORD_SESSION_KEY not in request.session:
             request.session[CONTEST_PASSWORD_SESSION_KEY] = {}
-        request.session[CONTEST_PASSWORD_SESSION_KEY][contest.id] = data["password"]
+        request.session[CONTEST_PASSWORD_SESSION_KEY][str(contest.id)] = data["password"]
         request.session.modified = True
         return self.success(True)
 
@@ -112,7 +112,7 @@ class ContestAccessAPI(AsyncAPIView):
         except Contest.DoesNotExist:
             return self.error("Contest does not exist")
         session_pass = request.session.get(CONTEST_PASSWORD_SESSION_KEY, {}).get(
-            contest.id
+            str(contest.id)
         )
         return self.success(
             {"access": check_contest_password(session_pass, contest.password)}
diff --git a/judge/dispatcher.py b/judge/dispatcher.py
index f394ff5..9206249 100644
--- a/judge/dispatcher.py
+++ b/judge/dispatcher.py
@@ -11,7 +11,7 @@ from django.utils import timezone
 
 from account.models import User
 from conf.models import JudgeServer
-from contest.models import ACMContestRank, ContestStatus
+from contest.models import ACMContestRank
 from options.options import SysOptions
 from problem.models import Problem, ProblemRuleType
 from problem.utils import parse_problem_template
@@ -238,7 +238,10 @@ class JudgeDispatcher(DispatcherBase):
             logger.error(f"Failed to push submission update: {str(e)}")
 
         if self.contest_id:
-            if self.contest.status != ContestStatus.CONTEST_UNDERWAY or \
+            # 以提交时刻（而非判题时刻）是否落在比赛时间窗内为准，
+            # 避免临界提交因判题排队延迟到比赛结束后才处理而被丢弃
+            in_contest = self.contest.start_time <= self.submission.create_time <= self.contest.end_time
+            if not in_contest or \
                     User.objects.get(id=self.submission.user_id).is_contest_admin(self.contest):
                 logger.info(
                     "Contest debug mode, id: " + str(self.contest_id) + ", submission id: " + self.submission.id)
@@ -397,7 +400,7 @@ class JudgeDispatcher(DispatcherBase):
             if is_accepted(self.submission.result):
                 rank.accepted_number += 1
                 info["is_ac"] = True
-                info["ac_time"] = (self.submission.create_time - self.contest.start_time).total_seconds()
+                info["ac_time"] = int((self.submission.create_time - self.contest.start_time).total_seconds())
                 rank.total_time += info["ac_time"] + info["error_number"] * 20 * 60
 
                 if problem.accepted_number == 1:
@@ -412,7 +415,7 @@ class JudgeDispatcher(DispatcherBase):
             if is_accepted(self.submission.result):
                 rank.accepted_number += 1
                 info["is_ac"] = True
-                info["ac_time"] = (self.submission.create_time - self.contest.start_time).total_seconds()
+                info["ac_time"] = int((self.submission.create_time - self.contest.start_time).total_seconds())
                 rank.total_time += info["ac_time"]
 
                 if problem.accepted_number == 1: