最长特殊序列 II

class Solution {
    boolean containsSub(String s,String p){
        int i,j;
        for(i=0,j=0;i<p.length()&&j<s.length();j++)
            if(s.charAt(j)==p.charAt(i))
                i++;
        if(i>=p.length())return true;
        return false;
    }
    void removeStr(String p,LinkedList<String>list){
        if(list.contains(p)){
            String s="";
            for(int i=0;i<list.size();i++){
                s=list.get(i);
                if(s.length()<p.length()&&containsSub(p,s)){
                    removeStr(s,list);
                }
            }
            list.remove(p);
        }
    }
    public int findLUSlength(String[] strs) {
        int n=strs.length;
        HashMap<String,Integer>map=new HashMap<>();
        for(String s:strs)
            if(map.containsKey(s))
                map.replace(s, map.get(s)+1);
            else
                map.put(s, 1);
        LinkedList<String>list=new LinkedList<>();
        for(String s:map.keySet())    
            list.addFirst(s);
        list.sort(new Comparator<String>(){

            @Override
            public int compare(String o1, String o2) {
                // TODO Auto-generated method stub
                return o2.length()-o1.length();
            }
            
        });
        int last=list.size(),i=0;
        while(i<list.size()){
            if(map.get(list.get(i))>1)
                removeStr(list.get(i),list);
            else
                i++;
            if(last==list.size())break;
            else last=list.size();
        }    
        if(list.size()==0)return -1;
        return list.getFirst().length();
    }
}