public class DeReapted {

    public static void main(String[] args) {
        List<String> as = new ArrayList<>();
        as.add("a");
        as.add("e");
        as.add("f");
        as.add("a");
        as.add("d");
        as.add("f");
        System.out.println("原始數(shù)組："+as);

        //1.將list轉(zhuǎn)換成set按厘；
        List<String> res1 = new ArrayList<>();
        Set<String> set1 = new HashSet<>();
        for(String s :as){
            if(!set1.contains(s)){
                set1.add(s);
            }else {
                res1.add(s);
            }
        }
        System.out.println("方法一：將list轉(zhuǎn)換成set:");
        System.out.println("去重?cái)?shù)組set1："+set1);
        System.out.println("重復(fù)元素"+res1);
        System.out.println();

        //2.將list的contains()吕晌；
        List<String> dere = new ArrayList<>();
        List<String> res = new ArrayList<>();
        for(String s: as){
            if(!dere.contains(s)){
                dere.add(s);
            }else {
                res.add(s);
            }
        }
        System.out.println("方法二：new list加入新元素钉迷，實(shí)質(zhì)還是通過(guò)contains方法對(duì)比");
        System.out.println("去重復(fù)數(shù)組dere：" +dere);
        System.out.println("不一樣的元素："+res);
        System.out.println();

        //3.通過(guò)i,j兩個(gè)指針循環(huán)：
        List<String> l3= new ArrayList<>();
        List<String> res2 = new ArrayList<>();
        for(int i =0;i<as.size();i++){
            for(int j=i+1;j<as.size();j++){
                if (as.get(j).equals(as.get(i))) {
                    res2.add(as.get(j));
                    as.remove(j);
                }
            }
        }
        System.out.println("方法三：雙循環(huán)：");
        System.out.println("去重復(fù)數(shù)組dere："+as);
        System.out.println("不一樣的元素："+res2);
        System.out.println();

        //4.利用Java8 的流：
        List ls4 = as.stream().distinct().collect(Collectors.toList());
        System.out.println("方法四：java8stream特性："+ls4);
    }
}