d713: 中位数

#include<iostream>
#include<queue>
#include<vector>
#include<limits>
#define endl '\n'
using namespace std;
int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    priority_queue<long long, vector<long long>,    less<long long>> l;
    priority_queue<long long, vector<long long>, greater<long long>> r;
    l.emplace(numeric_limits<long long>::min());
    r.emplace(numeric_limits<long long>::max());
    int n, cnt = 0;
    auto sort = [](auto & v) {
        for (size_t i = 0; i < v.size(); i++)
            for (size_t j = i; j < v.size(); j++)
                if (v[i] > v[j]) swap(v[i], v[j]);
    };
    while (cin >> n) {
        vector<long long> v{l.top(), r.top(), n};
        sort(v), l.pop(), r.pop();
        if ((++cnt) & 1)
            l.emplace(v[0]), l.emplace(v[1]), r.emplace(v[2]), cout << l.top() << endl;
        else
            l.emplace(v[0]), r.emplace(v[1]), r.emplace(v[2]), cout << (l.top() + r.top()) / 2 << endl;
    }
    return 0;
}