数据流中的中位数

 public class myComperator implements Comparator<Integer>{
        @Override //从大到小排序
        public int compare(Integer o1, Integer o2) {
            return o2-o1;
        }
    }
   //          ~~~~~~~~Maxheap   minheap~~~~~
    PriorityQueue<Integer> minHeap=new PriorityQueue<>();//根最小
    PriorityQueue<Integer> MaxHeap=new PriorityQueue<>(new myComperator());//根最大
    int count=0;
    public void Insert(Integer num) {
        if ((count&1)==0){//偶数,放小根堆
            minHeap.offer(num);
            MaxHeap.offer(minHeap.poll());
        }else {
            MaxHeap.offer(num);
            minHeap.offer(MaxHeap.poll());
        }
        count++;
    }

    public Double GetMedian() {
        return (count&1)==0?new Double((minHeap.peek() + MaxHeap.peek())+"")/2:new Double(MaxHeap.peek()+"");
    }

import java.util.*;
public class Solution {
 
     ArrayList<Integer> al = new ArrayList<Integer>();
    public void Insert(Integer num) {
        al.add(num);
        Collections.sort(al);
    }
 
   public Double GetMedian() {
        int mid = al.size()/2;
        if((al.size()&1) == 0){
            Integer n1 = al.get(mid);
            Integer n2 = al.get(mid - 1);
            double s = (Double.valueOf(n1 + "") + Double.valueOf(n2 + ""))/2;
            return s;
        }else{
            double s = Double.valueOf(al.get(mid) + "");
            return s;
        }
    }
}