递归算法代码实例

 1 //获取数据方法
 2     public List<TreeVo> tree(List<ListVo> list, String id, String state,
 3             String[] str, GetTreeVoInterface getTree) {
 4         ArrayList<TreeVo> listTree = new ArrayList<TreeVo>();
 5         //遍历原始数据
 6         for (int i = list.size(); i > 0; i--) {
 7             ListVo vo = list.get(i - 1);
 8             String pid = vo.getPid();
 9             //清除已处理数据
10             if (check(pid, id)) {
11                 list.remove(vo);
12                 TreeVo tree = getTree.getTreeVo(vo, str);
13                 listTree.add(tree);
14             }
15         }
16 
17         // 遍历子节点
18         for (TreeVo tree : listTree) {
19             //判断是否有数据,没有数据返回上一级
20             if (tree.getId() != null) {
21                 
22                 String id2 = tree.getId();
23                 int lastIndexOf = id2.lastIndexOf('/');
24                 String substring = id2.substring(lastIndexOf+1);
25                 //运用递归
26                 //难点在于递归应用的地方以及递归的返回数据
27                 //如果递归无终止条件,程序将会运行为死循环,无限循环,最终程序会跑死
28                 List<TreeVo> listTreeChildren = tree(list, substring, state,
29                         str, getTree);
30                 tree.setChildren(listTreeChildren);
31             }
32         }
33         return listTree;
34     }