ArrayList 相关应用

ArrayList 相关应用

一、ArrayList实现简单扑克牌

//牌类
class Card{
    public int rank; // 牌面值
    public String suit; // 花色
    @Override
    public String toString() {
        return String.format("[%s %d]", suit, rank);
    }
}
public class TestArraylist3 {
    public static final String[] SUITS = {"♠", "♥", "♣", "♦"};

    // 买一副牌（利用List特点生成一副牌）
    private static List<Card> buyDeck() {
        List<Card> deck = new ArrayList<>(52);
        for (int i = 0; i < 4; i++) {
            for (int j = 1; j <= 13; j++) {
                String suit = SUITS[i];
                int rank = j;
                Card card = new Card();
                card.rank = rank;
                card.suit = suit;
                deck.add(card);
            }
        }
        return deck;
    }
    private static void swap(List<Card> deck, int i, int j) {
        Card t = deck.get(i);
        deck.set(i, deck.get(j));
        deck.set(j, t);
    }
//洗牌操作
    private static void shuffle(List<Card> deck) {
        Random random = new Random(20190905);
        for (int i = deck.size() - 1; i > 0; i--) {
            int r = random.nextInt(i);
            swap(deck, i, r);
        }
    }

    public static void main(String[] args) {
        List<Card> deck = buyDeck();
        System.out.println("顺序牌展示:");
        System.out.println(deck);
        shuffle(deck);
        System.out.println("洗过的牌展示:");
        System.out.println(deck);
      // 三个人，每个人轮流抓 5 张牌
        List<List<Card>> hands = new ArrayList<>();
        hands.add(new ArrayList<>());
        hands.add(new ArrayList<>());
        hands.add(new ArrayList<>());
        for (int i = 0; i < 5; i++) {
            for (int j = 0; j < 3; j++) {
                hands.get(j).add(deck.remove(0));
            }
        }
        System.out.println("剩余的牌:");
        System.out.println(deck);
        System.out.println("A 手中的牌:");
        System.out.println(hands.get(0));
        System.out.println("B 手中的牌:");
        System.out.println(hands.get(1));
        System.out.println("C 手中的牌:");
        System.out.println(hands.get(2));
    }
}

结果展示：

二、 利用ArrayList储存学生信息

class Student{
    private String name;
    private int age;
    private double scaore;
    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", scaore=" + scaore +
                '}';
    }
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public double getScaore() {
        return scaore;
    }

    public void setScaore(double scaore) {
        this.scaore = scaore;
    }

    public Student(String name, int age, double scaore) {
        this.name = name;
        this.age = age;
        this.scaore = scaore;
    }
}
public class TestArraylist2 {
    public static void main(String[] args) {
        List<Student> list =new ArrayList<>(3);
        list.add(new Student("梨花",13,89.6));
        list.add(new Student("张三",34,76.5));
        list.add(new Student(" lisi ",45,90));
        System.out.println(list);
    }
}

三、删除字符串中的重复元素

删除字符串中与子字符串重复的元素

public class TestArraylist3 {
    public static ArrayList<Character> delete(String str1, String str2){
       ArrayList<Character> arrayList = new ArrayList<>();
        for (int i = 0; i < str1.length(); i++) {
            char ch = str1.charAt(i);
            //将字符转化为字符串
            if(!str2.contains(ch+"")){
                arrayList.add(ch);
            }
        }
        return arrayList;
    }
    public static void main(String[] args) {
        ArrayList<Character> ret = delete("welcome to bit","come");
        for(int i = 0; i < ret.size();i++){
            System.out.print(ret.get(i));
        }
    }
}