AcWing 106. 动态中位数

依次读入一个整数序列，每当已经读入的整数个数为奇数时，输出已读入的整数构成的序列的中位数。

#include<bits/stdc++.h>
using namespace std;    
priority_queue<int> down;
priority_queue<int,vector<int>,greater<int> > up;
int main()
{
    int t;scanf("%d",&t);
    while(t--)
    {
        int id,n;scanf("%d%d",&id,&n);
        printf("%d %d\n",id,(n+1)/2);

        int cnt=0;
        for(int i=1;i<=n;i++)
        {
            int x;scanf("%d",&x);
            if(down.empty()||x<=down.top())down.push(x);
            else up.push(x);
            if(down.size()>up.size()+1)up.push(down.top()),down.pop();
            if(up.size()>down.size())down.push(up.top()),up.pop();
            if(i%2)
            {
                printf("%d ",down.top());cnt++;
                if(cnt%10==0)putchar('\n');
            }
        }if(cnt%10)putchar('\n');
    }
    return 0;
}