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#include <iostream>
#include <vector>

class Solution {
    void DFS(int n, int i, std::vector<int>& path, 
            std::vector<std::vector<int>>& graph, std::vector<std::vector<int>>& res) {
        path.push_back(i);
        if (i == n - 1) {
            res.push_back(path);
        }
        for (auto& j : graph[i]) {
            DFS(n, j, path, graph, res);
        }
        path.pop_back();
    }
    
public:
    std::vector<std::vector<int>> allPathsSourceTarget(std::vector<std::vector<int>>& graph) {
        int n = graph.size();
        std::vector<std::vector<int>> res;
        std::vector<int> path;
        path.reserve(n);
        DFS(n, 0, path, graph, res);
        return res;
    }
};