Addition and sum

#include <bits/stdc++.h>
typedef long long ll;
using namespace std;

struct segTree {
    int size = 1;
    vector<ll> sums, ops;

    void init(int n) {
        while(size < n) {
            size *= 2;
        }
        ops.assign(2*size, 0);
        sums.assign(2*size, 0);
    }

    void modify(int l, int r, ll v, int x, int lx, int rx) {
        if(lx >= r || l >= rx) {
            return;
        }
        if(l <= lx && rx <= r) {
            ops[x] += v;
            sums[x] += v*(ll)(rx-lx);
            return;
        }
        int m = (lx+rx)/2;
        modify(l, r, v, 2*x+1, lx, m);
        modify(l, r, v, 2*x+2, m, rx);
        sums[x] = sums[2*x+1]+sums[2*x+2]+ops[x]*(ll)(rx-lx);
    }

    void modify(int l, int r, ll v) {
        modify(l, r, v, 0, 0, size);
    }

    ll getSum(int l, int r, int x, int lx, int rx) {
        if(l >= rx || lx >= r) {
            return 0;
        }
        if(l <= lx && rx <= r) {
            return sums[x];
        }
        int m = (lx+rx)/2;
        return getSum(l, r, 2*x+1, lx, m)+getSum(l, r, 2*x+2, m, rx)+ops[x]*(ll)(min(rx, r)-max(lx, l));
    }

    ll getSum(int l, int r) {
        return getSum(l, r, 0, 0, size);
    }
};

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);
    int n, m; cin >> n >> m;
    segTree st; st.init(n);
    while(m--) {
        int op; cin >> op;
        if(op == 1) {
            int l, r; ll v;
            cin >> l >> r >> v;
            st.modify(l, r, v);
        } else {
            int l, r; cin >> l >> r;
            cout << st.getSum(l, r) << "\n";
        }
    }
    return 0;
}