migrate 392 questions to pattern format

backend/data/questions/course-schedule-iv.yaml

@@ -6,9 +6,12 @@ leetcode_url: https://leetcode.com/problems/course-schedule-iv/
 categories:
   - graphs
 patterns:
-  - bfs
-  - dfs
-  - dynamic-programming
+  - slug: bfs
+    is_optimal: true
+  - slug: dfs
+    is_optimal: false
+  - slug: dynamic-programming
+    is_optimal: false
 
 function_signature: "def check_if_prerequisite(num_courses: int, prerequisites: list[list[int]], queries: list[list[int]]) -> list[bool]:"