1D-->1D List:
new ArrayList<>(1D_list)
1D List添加 2D List
List<List<Integer>> result;
result.add(new ArrayList<>(curResult))
set to list;
new ArrayList < > (map.keySet());
1D-->1D List:
new ArrayList<>(1D_list)
1D List添加 2D List
List<List<Integer>> result;
result.add(new ArrayList<>(curResult))
set to list;
new ArrayList < > (map.keySet());