Find Eventual Safe States
There is a directed graph of n nodes with each node labeled from 0 to n - 1. The graph is represented by a 0-indexed 2D integer array graph where graph[i] is an integer array of nodes adjacent to node i, meaning there is an edge from node i to each node in graph[i].
A node is a terminal node if there are no outgoing edges. A node is a safe node if every possible path starting from that node leads to a terminal node or another safe node.
Return an array containing all the safe nodes of the graph. The answer should be sorted in ascending order.
Example 1
Input
graph = [[1,2],[2,3],[5],[0],[5],[],[]]Output
[2,4,5,6]Nodes 5 and 6 are terminal nodes, and every path starting at nodes 2, 4, 5, and 6 leads to either node 5 or 6.
Example 2
Input
graph = [[1,2,3,4],[1,2],[3,4],[0,4],[]]Output
[4]Only node 4 is a terminal node, and every path starting at node 4 leads to node 4.
Constraints
- n == graph.length
- 1 <= n <= 10^4
- 0 <= graph[i].length <= n
- 0 <= graph[i][j] <= n - 1
- 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 * 10^4].
Asked at 6 companies
Practice questions like this out loud in a mock coding interview with a live AI interviewer. First one free.