A Leetcode hard problem on graph
Longest Cycle in a Graph
You are given a directed graph of
n nodes numbered from
n - 1, where each node has at most one outgoing edge.
The graph is represented with a given 0-indexed array
edges of size
n, indicating that there is a directed edge from node
i to node
edges[i]. If there is no outgoing edge from node
edges[i] == -1.
Return the length of the longest cycle in the graph. If no cycle exists, return