[leetcode] problem 797 – all paths from source to target

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.

Code

public List<List<Integer>> allPathsSourceTarget(int[][] graph) {
    List<List<Integer>> paths = new ArrayList<>();
    List<Integer> path = new ArrayList<>();
    path.add(0);
    findPath(paths, path, graph, 0);
    return paths;
}

private void (List<List<Integer>> paths, List<Integer> path, int[][] graph, int node) {
    if (node == graph.length - 1) {
        paths.add(new ArrayList<>(path));
        return;
    }

    for (int nextNode : graph[node]) {
        path.add(nextNode);
        findPath(paths, path, graph, nextNode);
        path.remove(path.size() - 1);
    }
}

[leetcode] problem 797 – all paths from source to target

Example

Note

Code

近期文章

近期评论

标签

热门

文章归档

分类目录

功能