rt 用的是树状数组做的

#include <bits/stdc++.h>
#define YES return void(cout << "Yes\n")
#define NO return void(cout << "No\n")
using namespace std;

using u64 = unsigned long long;
using PII = pair<int, int>;
using i64 = long long;

template<typename T>
struct BIT {
    const int n;
    vector<T> tree;
    BIT(int n) : n(n), tree(n + 1) {};
    T qry(int x) {
        T res = 0;
        for (int i = x; i > 0; i -= (i & -i))
            res += tree[i];
        return res;
    }
    void upd(int l, T z) {
        for (int i = l; i <= n; i += (i & -i))
            tree[i] += z;
    }
    T qryseg(int l, int r) {
        return qry(min(n, r)) - qry(max(0, l - 1));
    }
};

void solve() {
    int c, q;
    cin >> c >> q;

    BIT<i64> fen(2e5 + 10);
    multiset<i64, greater<i64>> mx;
    queue<pair<i64, i64>> que;

    int op, l = 1, r = 0;
    auto check = [&](int mid, i64 ask) {
        return fen.qryseg(l, mid) < ask;
    };

    for (int i = 1; i <= q; ++i) {
        cin >> op;
        if (op == 1) {
            i64 x; cin >> x;
            que.emplace(1, x);
            fen.upd(++r, x);
            mx.insert(x);
        }
        else if (op == 2) {
            i64 y; cin >> y;
            while (y) {
                auto& [S, T] = que.front();
                i64 d = min(T - S + 1, y);
                y -= d;
                if (y == 0) {
                    S += d;
                    fen.upd(l, -d);
                    break;
                } else {
                    mx.erase(mx.find(T));
                    que.pop(), ++l;
                }
            }
        }
        else if (op == 3) {
            i64 z; cin >> z;
            int L = l, R = r;
            while (L < R) {
                int mid = L + R + 1 >> 1;
                if (check(mid, z)) L = mid;
                else R = mid - 1;
            }
            if (L == l) {
                i64 d = que.front().second - que.front().first + 1;
                if (z > d) {
                    cout << z - d << '\n';
                } else {
                    cout << z + que.front().first - 1 << '\n';
                }
            }
            else {
                z -= fen.qryseg(l, L);
                cout << z << '\n';
            }
        }
        else if (op == 4) {
            cout << *mx.begin() << '\n';
        }
    }
}

signed main() {

    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);

    int t = 1; //cin >> t;
    while (t--) solve();

    return 0;
}