Deep copy HashSet
HashSet<Integer> set = new HashSet<Integer>();
HashSet<Integer> set2 = new HashSet<Integer>();
set2.addAll(set);
or
HashSet<Integer> set = new HashSet<Integer>();
HashSet<Integer> set2 = new HashSet<Integer>(set);
Deep copy HashMap
HashMap<Integer, Integer> map = new HashMap<>();
HashMap<Integer, Integer> map2 = new HashMap<>();
map2.putAll(map);
or
HashMap<Integer, Integer> map = new HashMap<>();
HashMap<Integer, Integer> map2 = new HashMap<>(map);
Anyway, Good luck, Richardo! -- 09/27/2016
网友评论
https://stackoverflow.com/questions/11296490/assigning-hashmap-to-hashmap
https://stackoverflow.com/questions/28288546/how-to-copy-hashmap-not-shallow-copy-in-java/28288729
读者这么多，为什么没人指出来!!
>: _ :<