集合-Set相关的面试题

1、在List内去除重复数字值，要求尽可能简单

import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;

public class TestC{
    public static void main(String[] args) {
       ArrayList<Integer> arrayList = new ArrayList<>();
       arrayList.add(1);
       arrayList.add(2);
       arrayList.add(3);
       arrayList.add(2);
       arrayList.add(5);
       arrayList.add(1);

       List list = updateList(arrayList);

       Iterator iterator = list.iterator();
       while(iterator.hasNext()){
    	   System.out.println(iterator.next());
       }
    }

	public static List updateList(List list){
	      HashSet set = new HashSet();
	      set.addAll(list);
	      return new ArrayList(set);
	}
	
}

运行结果;
1 2 3 5

2、

原文：https://www.cnblogs.com/52yu/p/13621935.html