每次添加一个数进入List数组,然后对数组进行排序,在计算中位数。

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Solution {

    List<Integer> list = new ArrayList<>();
    public void Insert(Integer num) {
        list.add(num);
        Collections.sort(list);
    }

    public Double GetMedian() {
        int len = list.size();
        int mid = len / 2;
        return len % 2 == 0 ? (double) (list.get(mid - 1) + list.get(mid)) / 2: (double) (list.get((len - 1) / 2)); 
    }

}