编辑代码

public class test{
    public static void main(String[] args) {
        int n = 4;
        findOptimalPath(n, 1, "");
    }

    public static void findOptimalPath(int n, int currLevel, String path) {
        if (currLevel > n) {
            System.out.println(path);
            return;
        }

        for (int i = 1; i <= currLevel; i++) {
            path += currLevel + " ";
        }
        path += "\n";

        findOptimalPath(n, currLevel + 1, path);
    }

}