# 1462. Course Schedule IV

https://leetcode.com/problems/course-schedule-iv

## Description

There are a total of `numCourses` courses you have to take, labeled from `0` to `numCourses - 1`. You are given an array `prerequisites` where `prerequisites[i] = [ai, bi]` indicates that you **must** take course `ai` first if you want to take course `bi`.

* For example, the pair `[0, 1]` indicates that you have to take course `0` before you can take course `1`.

Prerequisites can also be **indirect**. If course `a` is a prerequisite of course `b`, and course `b` is a prerequisite of course `c`, then course `a` is a prerequisite of course `c`.

You are also given an array `queries` where `queries[j] = [uj, vj]`. For the `jth` query, you should answer whether course `uj` is a prerequisite of course `vj` or not.

Return _a boolean array_ `answer`_, where_ `answer[j]` _is the answer to the_ `jth` _query._

**Example 1:**

![](https://assets.leetcode.com/uploads/2021/05/01/courses4-1-graph.jpg)

```
**Input:** numCourses = 2, prerequisites = [[1,0]], queries = [[0,1],[1,0]]
**Output:** [false,true]
**Explanation:** The pair [1, 0] indicates that you have to take course 1 before you can take course 0.
Course 0 is not a prerequisite of course 1, but the opposite is true.
```

**Example 2:**

```
**Input:** numCourses = 2, prerequisites = [], queries = [[1,0],[0,1]]
**Output:** [false,false]
**Explanation:** There are no prerequisites, and each course is independent.
```

**Example 3:**

![](https://assets.leetcode.com/uploads/2021/05/01/courses4-3-graph.jpg)

```
**Input:** numCourses = 3, prerequisites = [[1,2],[1,0],[2,0]], queries = [[1,0],[1,2]]
**Output:** [true,true]
```

**Constraints:**

* `2 <= numCourses <= 100`
* `0 <= prerequisites.length <= (numCourses * (numCourses - 1) / 2)`
* `prerequisites[i].length == 2`
* `0 <= ai, bi <= n - 1`
* `ai != bi`
* All the pairs `[ai, bi]` are **unique**.
* The prerequisites graph has no cycles.
* `1 <= queries.length <= 104`
* `0 <= ui, vi <= n - 1`
* `ui != vi`

## ac

```java
```
