# 797 All Paths From Source to Target

## 1. Question

Given a directed, acyclic graph of`N`nodes. Find all possible paths from node`0`to node`N-1`, and return them in any order.
The graph is given as follows: the nodes are 0, 1, ..., graph.length - 1. graph[i] is a list of all nodes j for which the edge (i, j) exists.
Example:
Input: [[1,2], , , []]
Output: [[0,1,3],[0,2,3]]
Explanation:
The graph looks like this:
0--->1
| |
v v
2--->3
There are two paths:
0 -> 1 ->3 and 0 -> 2 ->3.

## 2. Implementation

(1) Backtracking
class Solution {
public List<List<Integer>> allPathsSourceTarget(int[][] graph) {
List<List<Integer>> res = new ArrayList<>();
if (graph == null || graph.length == 0) {
return res;
}
int m = graph.length, n = graph.length;
List<Integer> path = new ArrayList<>();
getPaths(0, graph, path, res);
return res;
}
public void getPaths(int curNode, int[][] graph, List<Integer> path, List<List<Integer>> res) {
if (curNode == graph.length - 1) {
return;
}
for (int nextNode : graph[curNode]) {