如何将 List<List<String>>中包含相同元素的List进行搜索重组

Question

假设一个List里面包含多个List:
<"apple", "banana">,<"ball", "pen"> <"apple", "orange">, <"grape", "orange">,<"paper","ruler">,<"ink","pen">
如何将每个List进行重复比对，并将含有相同元素的List合并，最后形成一个新的List>：
<"apple","banana","orange","grape">,,<"paper","ruler">

也可理解为："A=B","C=D","A=E","F=E","G=H","I=D" =>
"A=B=E=F","C=D=I","G=H"

请诸位不吝指教，谢谢！

Answer 1

没考虑性能，仅供参考。

[code="java"]
public static void main(String[] args) {

List<Set<String>> lists = new ArrayList<Set<String>>() {
    {
        add(new HashSet<String>(Arrays.asList("apple", "banana")));
        add(new HashSet<String>(Arrays.asList("ball", "pen")));
        add(new HashSet<String>(Arrays.asList("apple", "orange")));
        add(new HashSet<String>(Arrays.asList("grape", "orange")));
        add(new HashSet<String>(Arrays.asList("paper", "ruler")));
        add(new HashSet<String>(Arrays.asList("ink", "pen")));
    }
};

System.out.println(merge(lists));

}

public static List> merge(List> lists) {

List<Set<String>> result = new ArrayList<Set<String>>();

Map<String, Set<String>> map = new HashMap<String, Set<String>>();
for (Set<String> list : lists) {

    // 寻找类似的列表。
    Set<String> simList = null;
    for (Entry<String, Set<String>> e : map.entrySet()) {
        if (list.contains(e.getKey())) {
            simList = e.getValue();
            simList.addAll(list);// 合并类似。
            break;
        }
    }

    // 没找到类似。
    if (simList == null) {
        result.add(list);// 结果中加入引用。
        simList = list;
    }

    // 已经合并过了，所以不再区分。
    for (String s : list) {
        map.put(s, simList);
    }
}

return result;

}
[/code]