There is a directed graph of n nodes labeled from $0$ to n $- 1$. The graph is represented by a $0$ indexed $2$D integer array graph, where graph[i] is an integer array of nodes adjacent to node i, meaning there is a directed edge from node i to each node in graph[i].

A node is considered a terminal node if it has no outgoing edges. A node is a safe node if every possible path starting from that node leads to a terminal node.

Return an array containing all the safe nodes of the graph, sorted in ascending order.

Constraints:

• n $==$ graph.length

• $1 \leq$ n $\leq 10^4$

• $0 \leq$ graph[i].length $\leq$ n

• $0 \leq$ graph[i][j] $\leq$ n $- 1$

• graph[i] is sorted in strictly increasing order.

• The graph may contain self loops.

• The total number of edges in the graph is in the range $[1, 4 \times 10^4]$.

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.