用户名不区分大小写；

修复更新problem时的一些问题

problem/serializers.py

@@ -39,7 +39,7 @@ class CreateOrEditProblemSerializer(serializers.Serializer):
     input_description = serializers.CharField()
     output_description = serializers.CharField()
     samples = serializers.ListField(child=CreateSampleSerializer(), allow_empty=False)
-    test_case_id = serializers.CharField(min_length=32, max_length=32)
+    test_case_id = serializers.CharField(max_length=32)
     test_case_score = serializers.ListField(child=CreateTestCaseScoreSerializer(), allow_empty=False)
     time_limit = serializers.IntegerField(min_value=1, max_value=1000 * 60)
     memory_limit = serializers.IntegerField(min_value=1, max_value=1024)
@@ -68,6 +68,11 @@ class CreateContestProblemSerializer(CreateOrEditProblemSerializer):
     contest_id = serializers.IntegerField()
 
 
+class EditContestProblemSerializer(CreateOrEditProblemSerializer):
+    id = serializers.IntegerField()
+    contest_id = serializers.IntegerField()
+
+
 class TagSerializer(serializers.ModelSerializer):
     class Meta:
         model = ProblemTag