本蒟蒻样例没过：

输出为：
0
2
8

Code:

#include<bits/stdc++.h>
using namespace std;
int n, m, selcet, x, y, k, t[400005], a[100005], addv[400005], sumv[400005], _sum;
void Judge2(int o, int l, int r) {
    if (r > l) {
        sumv[o] = sumv[o * 2] + sumv[o * 2 + 1];
    }
    sumv[o] += addv[o] * (r - l + 1);
}
void build_tree(int o, int l, int r) {
    if (l == r) {
        t[o] = a[l];
        return;
    }
    int mid = (l + r) / 2;
    build_tree(o * 2, l, mid);
    build_tree(o * 2 + 1, mid + 1, r);
    sumv[o] = sumv[o * 2] + sumv[o * 2 + 1];
}
void Judge1(int o, int l, int r, int x, int y) {
    if (x <= l && r <= y) {
        addv[o] += k;
    }
    else {
        int mid = (l + r) / 2;
        if (x <= mid) {
            Judge1(o * 2, l, mid, x, y);
        }
        if (y > mid) {
            Judge1(o * 2 + 1, mid + 1, r, x, y);
        }
    }
    Judge2(o, l, r);
}
void find(int o, int l, int r, int x, int y, int add) {
    if (x <= l && r <= y) {
        _sum += sumv[o] + add * (r - l + 1);
    }
    else {
        int mid = (l + r) / 2;
        if (x <= mid) {
            find(o * 2, l, mid, x, y, add + addv[o]);
        }
        if (y > mid) {
            find(o * 2 + 1, mid + 1, r, x, y, add + addv[o]);
        }
    }
}
int main() {
    cin >> n >> m;
    for (int i = 1, v; i <= n; i++) {
        cin >> a[i];
    }
    build_tree(1, 1, n);
    for (int i = 1; i <= m; i++) {
        cin >> selcet >> x >> y;
        if (selcet == 1) {
            cin >> k;
            Judge1(1, 1, n, x, y);
        }
        else {
            _sum = 0;
            find(1, 1, n, x, y, 0);
            cout << _sum << "\n";
        }
    }
    return 0;
}