Medium
Given a directed acyclic graph (DAG) of n
nodes labeled from 0
to n - 1
, find all possible paths from node 0
to node n - 1
and return them in any order.
The graph is given as follows: graph[i]
is a list of all nodes you can visit from node i
(i.e., there is a directed edge from node i
to node graph[i][j]
).
Example 1:
Input: graph = [[1,2],[3],[3],[]]
Output: [[0,1,3],[0,2,3]]
Explanation: There are two paths: 0 -> 1 -> 3 and 0 -> 2 -> 3.
Example 2:
Input: graph = [[4,3,1],[3,2,4],[3],[4],[]]
Output: [[0,4],[0,3,4],[0,1,3,4],[0,1,2,3,4],[0,1,4]]
Constraints:
n == graph.length
2 <= n <= 15
0 <= graph[i][j] < n
graph[i][j] != i
(i.e., there will be no self-loops).graph[i]
are unique.import java.util.ArrayList;
import java.util.List;
public class Solution {
private List<List<Integer>> res;
public List<List<Integer>> allPathsSourceTarget(int[][] graph) {
res = new ArrayList<>();
List<Integer> temp = new ArrayList<>();
temp.add(0);
// perform DFS
solve(graph, temp, 0);
return res;
}
private void solve(int[][] graph, List<Integer> temp, int lastNode) {
if (lastNode == graph.length - 1) {
res.add(new ArrayList<>(temp));
}
for (int link : graph[lastNode]) {
temp.add(link);
solve(graph, temp, link);
temp.remove(temp.size() - 1);
}
}
}