SegTree PA

  struct seg_pa {
	struct Data {
		ll sum;
		ll set_a, set_r, add_a, add_r;
		Data() : sum(0), set_a(LINF), set_r(0), add_a(0), add_r(0) {}
	};
	vector<Data> seg;
	int n;

	seg_pa(int n_) {
		n = n_;
		seg = vector<Data>(4*n);
	}

	void prop(int p, int l, int r) {
		int tam = r-l+1;
		ll &sum = seg[p].sum, &set_a = seg[p].set_a, &set_r = seg[p].set_r,
			&add_a = seg[p].add_a, &add_r = seg[p].add_r;

		if (set_a != LINF) {
			set_a += add_a, set_r += add_r;
			sum = set_a*tam + set_r*tam*(tam+1)/2;
			if (l != r) {
				int m = (l+r)/2;

				seg[2*p].set_a = set_a;
				seg[2*p].set_r = set_r;
				seg[2*p].add_a = seg[2*p].add_r = 0;

				seg[2*p+1].set_a = set_a + set_r * (m-l+1);
				seg[2*p+1].set_r = set_r;
				seg[2*p+1].add_a = seg[2*p+1].add_r = 0;
			}
			set_a = LINF, set_r = 0;
			add_a = add_r = 0;
		} else if (add_a or add_r) {
			sum += add_a*tam + add_r*tam*(tam+1)/2;
			if (l != r) {
				int m = (l+r)/2;

				seg[2*p].add_a += add_a;
				seg[2*p].add_r += add_r;

				seg[2*p+1].add_a += add_a + add_r * (m-l+1);
				seg[2*p+1].add_r += add_r;
			}
			add_a = add_r = 0;
		}
	}

	int inter(pair<int, int> a, pair<int, int> b) {
		if (a.first > b.first) swap(a, b);
		return max(0, min(a.second, b.second) - b.first + 1);
	}
	ll set(int a, int b, ll aa, ll rr, int p, int l, int r) {
		prop(p, l, r);
		if (b < l or r < a) return seg[p].sum;
		if (a <= l and r <= b) {
			seg[p].set_a = aa;
			seg[p].set_r = rr;
			prop(p, l, r);
			return seg[p].sum;
		}
		int m = (l+r)/2;
		int tam_l = inter({l, m}, {a, b});
		return seg[p].sum = set(a, b, aa, rr, 2*p, l, m) +
			set(a, b, aa + rr * tam_l, rr, 2*p+1, m+1, r);
	}
	void update_set(int l, int r, ll aa, ll rr) {
		set(l, r, aa, rr, 1, 0, n-1);
	}
	ll add(int a, int b, ll aa, ll rr, int p, int l, int r) {
		prop(p, l, r);
		if (b < l or r < a) return seg[p].sum;
		if (a <= l and r <= b) {
			seg[p].add_a += aa;
			seg[p].add_r += rr;
			prop(p, l, r);
			return seg[p].sum;
		}
		int m = (l+r)/2;
		int tam_l = inter({l, m}, {a, b});
		return seg[p].sum = add(a, b, aa, rr, 2*p, l, m) +
			add(a, b, aa + rr * tam_l, rr, 2*p+1, m+1, r);
	}
	void update_add(int l, int r, ll aa, ll rr) {
		add(l, r, aa, rr, 1, 0, n-1);
	}
	ll query(int a, int b, int p, int l, int r) {
		prop(p, l, r);
		if (b < l or r < a) return 0;
		if (a <= l and r <= b) return seg[p].sum;
		int m = (l+r)/2;
		return query(a, b, 2*p, l, m) + query(a, b, 2*p+1, m+1, r);
	}
	ll query(int l, int r) { return query(l, r, 1, 0, n-1); }
};