Сумма на отрезке, прибавление на отрезке (запросы)

#include <iostream>
#include <tuple>
#include <random>

using std::pair;
using std::cin;
using std::cout;
using std::vector;
using int64 = int64_t;
using std::max;
using std::min;

class SegmentTree {
public:
    int64 log_size;
    vector<int64> nodes = std::vector<int64>((2 << log_size) - 1);
    vector<int64> SubtreeAdd = std::vector<int64>((2 << log_size) - 1);

    static int64 IntLog(int64 n) {
        int64 temp = 1;
        int64 ans = 0;
        while (temp < n) {
            temp *= 2;
            ++ans;
        }
        return ans;
    }

    static int64 Pow2(int64 n) {
        return 1 << n;
    }

    explicit SegmentTree(const vector<int64> &vec) : log_size(IntLog(vec.size())) {
        std::copy(vec.begin(), vec.end(), nodes.begin() + (1 << log_size) - 1);
        for (int64 i = Pow2(log_size) - 2; i >= 0; --i) {
            nodes[i] = nodes[2 * i + 1] + nodes[2 * i + 2];
        }
    }

    void Modify(int64 l, int64 r, int64 val) {
        Modify(l, r, 0, 0, Pow2(log_size) - 1, val);
    }

    int64 GetSum(int64 l, int64 r) {
        return GetSum(l, r, 0, 0, Pow2(log_size) - 1);
    }

private:

    int64 GetSum(int64 l, int64 r, int64 n, int64 nl, int64 nr) {
        push(n, nl, nr);
        if (l > r) {
            return 0;
        }
        if (l == nl && r == nr) {
            return nodes[n];
        }
        int64 mid = (nl + nr) / 2;
        return GetSum(l, min(r, mid), n * 2 + 1, nl, mid) +
               GetSum(max(l, mid + 1), r, n * 2 + 2, mid + 1, nr);
    }

    void push(int64 v, int64 vl, int64 vr) {
        if (SubtreeAdd[v]) {
            nodes[v] += SubtreeAdd[v] * (vr - vl + 1);
            if (vl != vr) {
                SubtreeAdd[2 * v + 1] += SubtreeAdd[v];
                SubtreeAdd[2 * v + 2] += SubtreeAdd[v];
            }
            SubtreeAdd[v] = 0;
        }
    }

    void Modify(int64 l, int64 r, int64 n, int64 nl, int64 nr, int64 val) {
        push(n, nl, nr);
        if (l > nr || r < nl) {
            return;
        }
        if (l <= nl && r >= nr) {
            SubtreeAdd[n] += val;
            push(n, nl, nr);
            return;
        } else {
            int64 mid = (nl + nr) / 2;
            Modify(l, r, n * 2 + 1, nl, mid, val);
            Modify(l, r, n * 2 + 2, mid + 1, nr, val);
            nodes[n] = nodes[2 * n + 1] + nodes[2 * n + 2];
        }
    }


};

int main() {
    int64 n;
    cin >> n;
    vector<int64> vec(n);
    for (size_t i = 0; i < n; ++i) {
        cin >> vec[i];
    }
    SegmentTree st(vec);
    int k;
    cin >> k;
    for (size_t i = 0; i < k; ++i) {
        int num;
        cin >> num;
        if (num == 1) {
            int64 l, r;
            cin >> l >> r;
            cout << st.GetSum(l, r) << '\n';
        } else {
            int64 l, r, x;
            cin >> l >> r >> x;
            st.Modify(l, r, x);
        }
    }
    return 0;
}