All Paths From Source to Target
Similar Problems:
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.
Github: code.dennyzhang.com
Credits To: leetcode.com
Leave me comments, if you have better ways to solve.
## https://code.dennyzhang.com/all-paths-from-source-to-target
## Basic Ideas: dfs
## Complexity: Time O(n!), Space O(n)
class Solution:
def allPathsSourceTarget(self, graph):
"""
:type graph: List[List[int]]
:rtype: List[List[int]]
"""
length = len(graph)
if length == 0: return []
if length == 1: return [[0]]
self.res, self.l = [], []
self.dfs(0, graph)
return self.res
def dfs(self, node, graph):
if node == len(graph) - 1:
self.res.append(self.l + [node])
return
self.l.append(node)
for edge in graph[node]:
self.dfs(edge, graph)
self.l.pop(-1)
