【重点】【回溯】797.所有可能的路径

题目

class Solution:
    def allPathsSourceTarget(self, graph: List[List[int]]) -> List[List[int]]:
        n = len(graph) - 1
        res, path = [], [0]
        self.dfs(graph, 0, res, path, n)

        return res

    def dfs(self, graph, start, res, path, n):
        if start == n:
            res.append(path.copy())
            return
        next_idx_list = graph[start]
        for next_idx in next_idx_list:
            path.append(next_idx)
            self.dfs(graph, next_idx, res, path, n)
            path.pop()