package method;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.Comparator;

import java.util.List;

/***

 * 1.父类的引用指向子类的对象

 * 2.sort(List list)排序

 * 3.sort(List list, Comparator comparator);排序

 * 4.binarySearch,搜索指定元素索引,前提列表必须有序

 * 5.reverse反转

 * 6.重新洗牌shuffle

 * 7.swap交换,交换两个索引位置元素,Collections.swap(list, 1, 2);

 * @author Administrator

 *

 */

public class CollectionsDemo {

    public static void main(String[] args) {

        List list=new ArrayList();

        //添加测试数据

        list.add("a");

        list.add("b");

        list.add("d");

        list.add("c");

        list.add("e");

        System.out.println(Arrays.toString(list.toArray()));

        //sort排序,升序

        Collections.sort(list);

        System.out.println(Arrays.toString(list.toArray()));

        //使用sort降序排序

        Collections.sort(list, new Comparator<String>(){

            @Override

            public int compare(String o1, String o2) {

                // TODO Auto-generated method stub

                int result=o2.length()-o1.length();

                int length=result>0?o2.length():o1.length();

                char[]a1=o1.toCharArray();

                char[]a2=o2.toCharArray();

                for(int i=0;i<length;i++){

                    if(a1[i]>a2[i]){

                        return -1;

                    }else if(a1[i]==a2[i]){

                        return 0;

                    }else{

                        return 1;

                    }

                }

                return result;

            }

        });

        System.out.println(Arrays.toString(list.toArray()));

        //二分法检测元素索引

        int indexResult = Collections.binarySearch(list, "c");

        System.out.println(indexResult);

        //reverse反转

        Collections.reverse(list);

        System.out.println(Arrays.toString(list.toArray()));

        //重新洗牌shuffle

        Collections.shuffle(list);

        System.out.println(Arrays.toString(list.toArray()));

        //swap交换,交换两个索引位置元素

        Collections.swap(list, 1, 2);

        System.out.println(Arrays.toString(list.toArray()));

    }

}

package method;

import java.util.ArrayList;

import java.util.Collections;

/***

 * 模拟斗地主,洗牌

 * @author Administrator

 *

 */

public class Collections_card {

    public static void main(String[] args) {

        ArrayList cards = new ArrayList();

        ArrayList play1 = new ArrayList();

        ArrayList play2 = new ArrayList();

        ArrayList play3 = new ArrayList();

        ArrayList dipai = new ArrayList();

        //54张牌

        for(int i=0;i<54;i++){

            cards.add(i);

        }

        Collections.shuffle(cards);

        //三个玩家分牌

        for(int i=0;i<51;i+=3){

            play1.add(cards.get(i));

            play2.add(cards.get(i+1));

            play3.add(cards.get(i+2));

        }

        //底牌

        for(int i=51;i<54;i++){

            dipai.add(cards.get(i));

        }

        //输出检查效果

        System.out.println("玩家一:"+play1);

        System.out.println("玩家二:"+play2);

        System.out.println("玩家三:"+play3);

        System.out.println("底牌:"+dipai);

    }

}