# 0802. Find Eventual Safe States

https://leetcode.com/problems/find-eventual-safe-states

## Description

We start at some node in a directed graph, and every turn, we walk along a directed edge of the graph. If we reach a terminal node (that is, it has no outgoing directed edges), we stop.

We define a starting node to be **safe** if we must eventually walk to a terminal node. More specifically, there is a natural number `k`, so that we must have stopped at a terminal node in less than `k` steps for **any choice of where to walk**.

Return _an array containing all the safe nodes of the graph_. The answer should be sorted in **ascending** order.

The directed graph has `n` nodes with labels from `0` to `n - 1`, where `n` is the length of `graph`. The graph is given in the following form: `graph[i]` is a list of labels `j` such that `(i, j)` is a directed edge of the graph, going from node `i` to node `j`.

**Example 1:**

![Illustration of graph](https://s3-lc-upload.s3.amazonaws.com/uploads/2018/03/17/picture1.png)

```
**Input:** graph = [[1,2],[2,3],[5],[0],[5],[],[]]
**Output:** [2,4,5,6]
**Explanation:** The given graph is shown above.
```

**Example 2:**

```
**Input:** graph = [[1,2,3,4],[1,2],[3,4],[0,4],[]]
**Output:** [4]
```

**Constraints:**

* `n == graph.length`
* `1 <= n <= 104`
* `0 <= graph[i].length <= n`
* `graph[i]` is sorted in a strictly increasing order.
* The graph may contain self-loops.
* The number of edges in the graph will be in the range `[1, 4 * 104]`.

## ac

```java
```
