Add frozen subtasks

judge/migrations/0141_contestproblem_frozen_subtasks.py

@@ -0,0 +1,24 @@
+# Generated by Django 3.2.16 on 2022-12-20 06:15
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("judge", "0140_alter_contest_format_name"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="contestproblem",
+            name="frozen_subtasks",
+            field=models.CharField(
+                blank=True,
+                help_text="Only for format new IOI. Separated by commas, e.g: 2, 3",
+                max_length=20,
+                null=True,
+                verbose_name="frozen subtasks",
+            ),
+        ),
+    ]