- Difficulty: Hard
- Tags: LeetCode, Hard, Graph, Memoization, Dynamic Programming, leetcode-2876, O(n), Hash Table, Stack
Problem
There is a directed graph consisting of n
nodes numbered from 0
to n - 1
and n
directed edges.
You are given a 0-indexed array edges
where edges[i]
indicates that there is an edge from node i
to node edges[i]
.
Consider the following process on the graph:
- You start from a node
x
and keep visiting other nodes through edges until you reach a node that you have already visited before on this same process.
Return an array answer
where answer[i]
is the number of different nodes that you will visit if you perform the process starting from node i
.
Example 1:
Input: edges = [1,2,0,0] Output: [3,3,3,4] Explanation: We perform the process starting from each node in the following way: - Starting from node 0, we visit the nodes 0 -> 1 -> 2 -> 0. The number of different nodes we visit is 3. - Starting from node 1, we visit the nodes 1 -> 2 -> 0 -> 1. The number of different nodes we visit is 3. - Starting from node 2, we visit the nodes 2 -> 0 -> 1 -> 2. The number of different nodes we visit is 3. - Starting from node 3, we visit the nodes 3 -> 0 -> 1 -> 2 -> 0. The number of different nodes we visit is 4.
Example 2:
Input: edges = [1,2,3,4,0] Output: [5,5,5,5,5] Explanation: Starting from any node we can visit every node in the graph in the process.
Constraints:
n == edges.length
2 <= n <= 105
0 <= edges[i] <= n - 1
edges[i] != i