Sgt 模板代码

struct Sgt{
	int lazyTag;
	int val;
}t[maxn];

void pushUp(int x, int l, int r){
	t[x].val = t[x].lazyTag * (r - l + 1) + t[x * 2].val + t[x * 2 + 1].val;
}

void pushDown(int x, int l, int r){
	int mid = l + r >> 1;
	t[x * 2].lazyTag += t[x].lazyTag;
	t[x * 2 + 1].lazyTag += t[x].lazyTag;
	t[x * 2].val += t[x].lazyTag * (mid - l + 1);
	t[x * 2 + 1].val += t[x].lazyTag * (r - mid);
	t[x].lazyTag = 0;
}

void Build(int x, int l, int r){
	if (l == r){
      	t[x].val = 0;
		t[x].lazyTag = 0;
		return ;
	}
	t[x].lazyTag = 0;
	int mid = l + r >> 1;
	Build(x * 2, l, mid);
	Build(x * 2 + 1, mid + 1, r);
	pushUp(x, l, r);
}

void update(int x, int l, int r, int L, int R, int k){
	if (L <= l && r <= R){
		t[x].lazyTag += k;
		t[x].val += k * (r - l + 1);
		return ;
	}
	int mid = l + r >> 1;
	if (L <= mid) update(x * 2, l, mid, L, R, k);
	if (mid < R) update(x * 2 + 1, mid + 1, r, L, R, k);
	pushUp(x, l, r);
} 

int query(int x, int l, int r, int L, int R){
	if (L <= l && r <= R){
		return t[x].val;
	}
	pushDown(x, l, r);
	int mid = l + r >> 1;
	int res = 0;
	if (L <= mid) res += query(x * 2, l, mid, L, R);
	if (mid < R) res += query(x * 2 + 1, mid + 1, r, L, R);
	return res;
}