797. All Paths From Source to Target(圖的搜尋、dfs)
阿新 • • 發佈:2018-11-10
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], [3], [3], []]
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.
Note:
- The number of nodes in the graph will be in the range [2, 15].
- You can print different paths in any order, but you should keep the order of nodes inside one path.
class Solution: def allPathsSourceTarget(self, graph): """ :type graph: List[List[int]] :rtype: List[List[int]] """ res = [] def dfs(pos,path): if pos == len(graph)-1: res.append(path) return else: for i in graph[pos]: dfs(i,path+[i]) dfs(0,[0]) return res