DFS：打印所有完整路径

Question

下面的函数打印所有的子路径。是否可以只显示完整的路径，即A->B->C（包含以下所需的输出）。

findPaths(List<Integer>[] adjacencyList, int u, List<String> path) throws IOException {
        print(path+" "+path.size()+ "\n");
        for (Integer v : adjacencyList[u]) {
            path.add(mapIndexToCode.get(v));
            findPaths(adjacencyList, v, path, writer);
            path.remove(mapIndexToCode.get(v));
        }
    }

OUTPUT
A 1
A B 2
A B C 3

E 1
E F 2

REQUIRED OUTPUT
A B C 3

E F 2

Answer 1

您可以在打印前设置一个条件,以检查您是否位于路径的末尾：

findPaths(List<Integer>[] adjacencyList, int u, List<String> path) throws IOException {
        if (adjacencyList[u].isEmpty()) {
           print(path+" "+path.size()+ "\n");
        }
        else {
        for (Integer v : adjacencyList[u]) {
            path.add(mapIndexToCode.get(v));
            findPaths(adjacencyList, v, path, writer);
            path.remove(mapIndexToCode.get(v));
        }
        }
    }