LeetCode797. All Paths From Source to Target

本文介绍: 【代码】Le e tCode797. All Path s From Sour ce to Tar get。

文章 目录

- 一、题目
- 二、题解

一、题目

Gi v en a direct e d acycli c graph (DAG) of n node s labeled from 0 to n – 1, find all p oss i ble paths from no de 0 to no de n – 1 and return th em in any order.

The graph i s g i ven a s follo ws: graph[i] i s a list of all no des you can vi s it from no de i (i.e., there is a directed edge from node i to node graph[i][j]).

Ex ample 1:

Input: graph = [[1,2],[3],[3],[]]
Output: [[0,1,3],[0,2,3]]
Ex planation: There are two path s: 0 -> 1 -> 3 and 0 -> 2 -> 3.
Ex ample 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]]

Con s train ts:

n == graph.length
2 <= n <= 15
0 <= graph[i][j] < n
graph[i][j] != i (i.e., there will be no self–loop s).
All the elements of graph[i] are unique.
The input g r aph is guaranteed to be a DAG.

二、题解

class Solution {
public:
    vector<vector<int&gt;&gt; res;
    vector<int&gt; path;
    void dfs(vector<vector<int>>&amp; graph,int x){
        if(x == graph.size() - 1){
            res.push_back(path);
            return;
        }
        for(int i = 0;i < graph[x].size();i++){
            path.push_back(graph[x][i]);
            dfs(graph,graph[x][i]);
            path.pop_back();
        }
    }
    vector<vector<int>> allPathsSourceTarget(vector<vector<int>>&amp; graph) {
        path.push_back(0);
        dfs(graph,0);
        return res;
    }
};