![\"\"](\"https://assets.leetcode.com/uploads/2022/06/08/graph4drawio-5.png\")
You are given a directed graph of n nodes numbered from 0 to 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 i, then edges[i] == -1.
Return the length of the longest cycle in the graph. If no cycle exists, return -1.
A cycle is a path that starts and ends at the same node.
\n\n\n
Example 1:
\n\n\nInput: edges = [3,3,4,2,3]\nOutput: 3\nExplanation: The longest cycle in the graph is the cycle: 2 -> 4 -> 3 -> 2.\nThe length of this cycle is 3, so 3 is returned.\n\n\n
Example 2:
\n![\"\"](\"https://assets.leetcode.com/uploads/2022/06/07/graph4drawio-1.png\")
\n\nInput: edges = [2,-1,3,1]\nOutput: -1\nExplanation: There are no cycles in this graph.\n\n\n
\n
Constraints:
\n\nn == edges.length2 <= n <= 105-1 <= edges[i] < nedges[i] != i给你一个 n 个节点的 有向图 ，节点编号为 0 到 n - 1 ，其中每个节点 至多 有一条出边。
图用一个大小为 n 下标从 0 开始的数组 edges 表示，节点 i 到节点 edges[i] 之间有一条有向边。如果节点 i 没有出边，那么 edges[i] == -1 。
请你返回图中的 最长 环，如果没有任何环，请返回 -1 。
一个环指的是起点和终点是 同一个 节点的路径。
\n\n\n\n
示例 1：
\n\n
\n输入：edges = [3,3,4,2,3]\n输出去：3\n解释：图中的最长环是：2 -> 4 -> 3 -> 2 。\n这个环的长度为 3 ，所以返回 3 。\n\n\n
示例 2：
\n\n
\n输入：edges = [2,-1,3,1]\n输出：-1\n解释：图中没有任何环。\n\n\n
\n\n
提示：
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