Course Schedule

Rotting Oranges

Maximum Depth of Binary Tree

Determine whether all courses can be completed given prerequisite pairs.

There are `numCourses` courses labeled from `0` to `numCourses - 1`. Each pair `[course, prerequisite]` means the prerequisite must be completed first. Return whether every course can be finished.

## Example
```
Input: {"numCourses":2,"prerequisites":[[1,0]]}
Output: true
```

**Constraints**
- 1 <= numCourses <= 2000
- 0 <= prerequisites.length <= 5000
- Pairs are unique and contain valid distinct labels.

**Follow-up**
How would you return one valid course order?

- Identify the required output and the state that changes.
- Use the examples to rule out tempting but incorrect interpretations.

Understand the Goal

- This problem is best exposed by Kahn topological sort removes zero-indegree courses.
- Maintain only the state needed for the next operation.

Choose the Core Pattern

- Process each state once when possible.
- Record state before scheduling dependent work to avoid duplicates.

Build the Algorithm

- Verify the smallest input, impossible cases, and repeated values where allowed.
- Keep output ordering deterministic.